Fix the import in sql example.

Author: Davies Liu <davies@databricks.com>

Closes #5230 from davies/fix_sql_example and squashes the following commits:

7ecc5f4 [Davies Liu] fix sql example

Deprecate inferSchema() and applySchema(), use createDataFrame() instead, which could take an optional `schema` to create an DataFrame from an RDD. The `schema` could be StructType or list of names of columns.

Author: Davies Liu <davies@databricks.com>

Closes #4498 from davies/create and squashes the following commits:

08469c1 [Davies Liu] remove Scala/Java API for now
c80a7a9 [Davies Liu] fix hive test
d1bd8f2 [Davies Liu] cleanup applySchema
9526e97 [Davies Liu] createDataFrame from RDD with columns

This pull request redesigns the existing Spark SQL dsl, which already provides data frame like functionalities.

TODOs:
With the exception of Python support, other tasks can be done in separate, follow-up PRs.
- [ ] Audit of the API
- [ ] Documentation
- [ ] More test cases to cover the new API
- [x] Python support
- [ ] Type alias SchemaRDD

Author: Reynold Xin <rxin@databricks.com>
Author: Davies Liu <davies@databricks.com>

Closes #4173 from rxin/df1 and squashes the following commits:

0a1a73b [Reynold Xin] Merge branch 'df1' of github.com:rxin/spark into df1
23b4427 [Reynold Xin] Mima.
828f70d [Reynold Xin] Merge pull request #7 from davies/df
257b9e6 [Davies Liu] add repartition
6bf2b73 [Davies Liu] fix collect with UDT and tests
e971078 [Reynold Xin] Missing quotes.
b9306b4 [Reynold Xin] Remove removeColumn/updateColumn for now.
a728bf2 [Reynold Xin] Example rename.
e8aa3d3 [Reynold Xin] groupby -> groupBy.
9662c9e [Davies Liu] improve DataFrame Python API
4ae51ea [Davies Liu] python API for dataframe
1e5e454 [Reynold Xin] Fixed a bug with symbol conversion.
2ca74db [Reynold Xin] Couple minor fixes.
ea98ea1 [Reynold Xin] Documentation & literal expressions.
2b22684 [Reynold Xin] Got rid of IntelliJ problems.
02bbfbc [Reynold Xin] Tightening imports.
ffbce66 [Reynold Xin] Fixed compilation error.
59b6d8b [Reynold Xin] Style violation.
b85edfb [Reynold Xin] ALS.
8c37f0a [Reynold Xin] Made MLlib and examples compile
6d53134 [Reynold Xin] Hive module.
d35efd5 [Reynold Xin] Fixed compilation error.
ce4a5d2 [Reynold Xin] Fixed test cases in SQL except ParquetIOSuite.
66d5ef1 [Reynold Xin] SQLContext minor patch.
c9bcdc0 [Reynold Xin] Checkpoint: SQL module compiles!

Author: Daoyuan Wang <daoyuan.wang@intel.com>

Closes #2834 from adrian-wang/sqlpypath and squashes the following commits:

da7aa95 [Daoyuan Wang] fix file path using path.join

SQL example code for Python, as shown on [SQL Programming Guide](https://spark.apache.org/docs/1.0.2/sql-programming-guide.html)

Author: jyotiska <jyotiska123@gmail.com>

Closes #2521 from jyotiska/sql_example and squashes the following commits:

1471dcb [jyotiska] added imports for sql
b25e436 [jyotiska] pep 8 compliance
43fd10a [jyotiska] lines broken to maintain 80 char limit
b4fdf4e [jyotiska] removed blank lines
83d5ab7 [jyotiska] added inferschema and applyschema to the demo
306667e [jyotiska] replaced blank line with end line
c90502a [jyotiska] fixed new line
4939a70 [jyotiska] added new line at end for python style
0b46148 [jyotiska] fixed appname for python sql example
8f67b5b [jyotiska] added python sql example