[SPARK-3412] [PySpark] Replace Epydoc with Sphinx to generate Python API docs

Retire Epydoc, use Sphinx to generate API docs.

Refine Sphinx docs, also convert some docstrings into Sphinx style.

It looks like:
![api doc](https://cloud.githubusercontent.com/assets/40902/4538272/9e2d4f10-4dec-11e4-8d96-6e45a8fe51f9.png)

Author: Davies Liu <davies.liu@gmail.com>

Closes #2689 from davies/docs and squashes the following commits:

bf4a0a5 [Davies Liu] fix links
3fb1572 [Davies Liu] fix _static in jekyll
65a287e [Davies Liu] fix scripts and logo
8524042 [Davies Liu] Merge branch 'master' of github.com:apache/spark into docs
d5b874a [Davies Liu] Merge branch 'master' of github.com:apache/spark into docs
4bc1c3c [Davies Liu] refactor
746d0b6 [Davies Liu] @param -> :param
240b393 [Davies Liu] replace epydoc with sphinx doc

1 files changed, 9 insertions, 9 deletions

diff --git a/python/pyspark/mllib/util.py b/python/pyspark/mllib/util.py
index 8233d4e81f..1357fd4fbc 100644
--- a/python/pyspark/mllib/util.py
+++ b/python/pyspark/mllib/util.py
@@ -77,10 +77,10 @@ class MLUtils(object):
         method parses each line into a LabeledPoint, where the feature
         indices are converted to zero-based.
 
-        @param sc: Spark context
-        @param path: file or directory path in any Hadoop-supported file
+        :param sc: Spark context
+        :param path: file or directory path in any Hadoop-supported file
                      system URI
-        @param numFeatures: number of features, which will be determined
+        :param numFeatures: number of features, which will be determined
                             from the input data if a nonpositive value
                             is given. This is useful when the dataset is
                             already split into multiple files and you
@@ -88,7 +88,7 @@ class MLUtils(object):
                             features may not present in certain files,
                             which leads to inconsistent feature
                             dimensions.
-        @param minPartitions: min number of partitions
+        :param minPartitions: min number of partitions
         @return: labeled data stored as an RDD of LabeledPoint
 
         >>> from tempfile import NamedTemporaryFile
@@ -126,8 +126,8 @@ class MLUtils(object):
         """
         Save labeled data in LIBSVM format.
 
-        @param data: an RDD of LabeledPoint to be saved
-        @param dir: directory to save the data
+        :param data: an RDD of LabeledPoint to be saved
+        :param dir: directory to save the data
 
         >>> from tempfile import NamedTemporaryFile
         >>> from fileinput import input
@@ -149,10 +149,10 @@ class MLUtils(object):
         """
         Load labeled points saved using RDD.saveAsTextFile.
 
-        @param sc: Spark context
-        @param path: file or directory path in any Hadoop-supported file
+        :param sc: Spark context
+        :param path: file or directory path in any Hadoop-supported file
                      system URI
-        @param minPartitions: min number of partitions
+        :param minPartitions: min number of partitions
         @return: labeled data stored as an RDD of LabeledPoint
 
         >>> from tempfile import NamedTemporaryFile