[SPARK-10415] [PYSPARK] [MLLIB] [DOCS] Enhance Navigation Sidebar in PySpark API

These are CSS/JavaScript changes changes to make navigation in the PySpark API a bit simpler by adding the following to the sidebar:

* Classes
* Functions
* Tags to highlight experimental features

![screen shot 2015-09-02 at 08 50 12](https://cloud.githubusercontent.com/assets/11915197/9634781/301f853a-518b-11e5-8d5c-fda202f6202f.png)

Online example here: https://dl.dropboxusercontent.com/u/20821334/pyspark-api-nav-enhance/pyspark.mllib.html

(The contribution is my original work and that I license the work to the project under the project's open source license)

Author: noelsmith <mail@noelsmith.com>

Closes #8571 from noel-smith/pyspark-api-nav-enhance.

python/docs/_static/pyspark.css

+/*
+ Licensed to the Apache Software Foundation (ASF) under one or more
+ contributor license agreements.  See the NOTICE file distributed with
+ this work for additional information regarding copyright ownership.
+ The ASF licenses this file to You under the Apache License, Version 2.0
+ (the "License"); you may not use this file except in compliance with
+ the License.  You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+ Unless required by applicable law or agreed to in writing, software
+ distributed under the License is distributed on an "AS IS" BASIS,
+ WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ See the License for the specific language governing permissions and
+ limitations under the License.
+*/
+
+body {
+    background-color: #ffffff;
+}
+
+div.sphinxsidebar {
+    width: 274px;
+}
+
+div.bodywrapper {
+    margin: 0 0 0 274px;
+}
+
+div.sphinxsidebar ul {
+    margin-right: 10px;
+}
+
+div.sphinxsidebar li a {
+    word-break: break-all;
+}
+
+span.pys-tag {
+    font-size: 11px;
+    font-weight: bold;
+    margin: 0 0 0 2px;
+    padding: 1px 3px 1px 3px;
+    -moz-border-radius: 3px;
+    -webkit-border-radius: 3px;
+    border-radius: 3px;
+    text-align: center;
+    text-decoration: none;
+}
+
+span.pys-tag-experimental {
+    background-color: rgb(37, 112, 128);
+    color: rgb(255, 255, 255);
+}
+
+span.pys-tag-deprecated {
+    background-color: rgb(238, 238, 238);
+    color: rgb(62, 67, 73);
+}
+
+div.pys-note-experimental {
+    background-color: rgb(88, 151, 165);
+    border-color: rgb(59, 115, 127);
+    color: rgb(255, 255, 255);
+}
+
+div.pys-note-deprecated {
+}
+
+.hasTooltip {
+    position:relative;
+}
+.hasTooltip span {
+    display:none;
+}
+
+.hasTooltip:hover span.tooltip {
+    display: inline-block;
+    -moz-border-radius: 2px;
+    -webkit-border-radius: 2px;
+    border-radius: 2px;
+    background-color: rgb(250, 250, 250);
+    color: rgb(68, 68, 68);
+    font-weight: normal;
+    box-shadow: 1px 1px 3px rgb(127, 127, 127);
+    position: absolute;
+    padding: 0 3px 0 3px;
+    top: 1.3em;
+    left: 14px;
+    z-index: 9999
+}

python/docs/_static/pyspark.js

+/*
+ Licensed to the Apache Software Foundation (ASF) under one or more
+ contributor license agreements.  See the NOTICE file distributed with
+ this work for additional information regarding copyright ownership.
+ The ASF licenses this file to You under the Apache License, Version 2.0
+ (the "License"); you may not use this file except in compliance with
+ the License.  You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+ Unless required by applicable law or agreed to in writing, software
+ distributed under the License is distributed on an "AS IS" BASIS,
+ WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ See the License for the specific language governing permissions and
+ limitations under the License.
+*/
+
+$(function (){
+
+    function startsWith(s, prefix) {
+        return s && s.indexOf(prefix) === 0;
+    }
+
+    function buildSidebarLinkMap() {
+        var linkMap = {};
+        $('div.sphinxsidebar a.reference.internal').each(function (i,a)  {
+            var href = $(a).attr('href');
+            if (startsWith(href, '#module-')) {
+                var id = href.substr(8);
+                linkMap[id] = [$(a), null];
+            }
+        })
+        return linkMap;
+    };
+
+    function getAdNoteDivs(dd) {
+        var noteDivs = {};
+        dd.find('> div.admonition.note > p.last').each(function (i, p) {
+            var text = $(p).text();
+            if (!noteDivs.experimental && startsWith(text, 'Experimental')) {
+                noteDivs.experimental = $(p).parent();
+            }
+            if (!noteDivs.deprecated && startsWith(text, 'Deprecated')) {
+                noteDivs.deprecated = $(p).parent();
+            }
+        });
+        return noteDivs;
+    }
+
+    function getParentId(name) {
+        var last_idx = name.lastIndexOf('.');
+        return last_idx == -1? '': name.substr(0, last_idx);
+    }
+
+    function buildTag(text, cls, tooltip) {
+        return '<span class="pys-tag ' + cls + ' hasTooltip">' + text + '<span class="tooltip">'
+            + tooltip + '</span></span>'
+    }
+
+
+    var sidebarLinkMap = buildSidebarLinkMap();
+
+    $('dl.class, dl.function').each(function (i,dl)  {
+
+        dl = $(dl);
+        dt = dl.children('dt').eq(0);
+        dd = dl.children('dd').eq(0);
+        var id = dt.attr('id');
+        var desc = dt.find('> .descname').text();
+        var adNoteDivs = getAdNoteDivs(dd);
+
+        if (id) {
+            var parent_id = getParentId(id);
+
+            var r = sidebarLinkMap[parent_id];
+            if (r) {
+                if (r[1] === null) {
+                    r[1] = $('<ul/>');
+                    r[0].parent().append(r[1]);
+                }
+                var tags = '';
+                if (adNoteDivs.experimental) {
+                    tags += buildTag('E', 'pys-tag-experimental', 'Experimental');
+                    adNoteDivs.experimental.addClass('pys-note pys-note-experimental');
+                }
+                if (adNoteDivs.deprecated) {
+                    tags += buildTag('D', 'pys-tag-deprecated', 'Deprecated');
+                    adNoteDivs.deprecated.addClass('pys-note pys-note-deprecated');
+                }
+                var li = $('<li/>');
+                var a = $('<a href="#' + id + '">' + desc + '</a>');
+                li.append(a);
+                li.append(tags);
+                r[1].append(li);
+                sidebarLinkMap[id] = [a, null];
+            }
+        }
+    });
+});

python/docs/_templates/layout.html

+{% extends "!layout.html" %}
+{% set script_files = script_files + ["_static/pyspark.js"] %}
+{% set css_files = css_files + ['_static/pyspark.css'] %}
+{% block rootrellink %}
+    {{ super() }}
+{% endblock %}

python/docs/conf.py

@@ -23,7 +23,7 @@ sys.path.insert(0, os.path.abspath('.'))
 # -- General configuration ------------------------------------------------
 
 # If your documentation needs a minimal Sphinx version, state it here.
-#needs_sphinx = '1.0'
+needs_sphinx = '1.2'
 
 # Add any Sphinx extension module names here, as strings. They can be
 # extensions coming with Sphinx (named 'sphinx.ext.*') or your custom
@@ -135,7 +135,7 @@ html_logo = "../../docs/img/spark-logo-hd.png"
 # Add any paths that contain custom static files (such as style sheets) here,
 # relative to this directory. They are copied after the builtin static files,
 # so a file named "default.css" will overwrite the builtin "default.css".
-#html_static_path = ['_static']
+html_static_path = ['_static']
 
 # Add any extra paths that contain custom files (such as robots.txt or
 # .htaccess) here, relative to this directory. These files are copied