[SQL] Fix compiling of catalyst docs.

Author: Michael Armbrust <michael@databricks.com>

Closes #1653 from marmbrus/fixDocs and squashes the following commits:

0aa1feb [Michael Armbrust] Fix compiling of catalyst docs.

project/SparkBuild.scala

@@ -194,7 +194,10 @@ object Flume {
 
 object Catalyst {
   lazy val settings = Seq(
-    addCompilerPlugin("org.scalamacros" % "paradise" % "2.0.1" cross CrossVersion.full))
+    addCompilerPlugin("org.scalamacros" % "paradise" % "2.0.1" cross CrossVersion.full),
+    // Quasiquotes break compiling scala doc...
+    // TODO: Investigate fixing this.
+    sources in (Compile, doc) ~= (_ filter (_.getName contains "codegen")))
 }
 
 object SQL {