SPARK-1903 Document Spark's network connections

https://issues.apache.org/jira/browse/SPARK-1903

Author: Andrew Ash <andrew@andrewash.com>

Closes #856 from ash211/SPARK-1903 and squashes the following commits:

6e7782a [Andrew Ash] Add the technology used on each port
1d9b5d3 [Andrew Ash] Document port for history server
56193ee [Andrew Ash] spark.ui.port becomes worker.ui.port and master.ui.port
a774c07 [Andrew Ash] Wording in network section
90e8237 [Andrew Ash] Use real :toc instead of the hand-written one
edaa337 [Andrew Ash] Master -> Standalone Cluster Master
57e8869 [Andrew Ash] Port -> Default Port
3d4d289 [Andrew Ash] Title to title case
c7d42d9 [Andrew Ash] [WIP] SPARK-1903 Add initial port listing for documentation
a416ae9 [Andrew Ash] Word wrap to 100 lines

docs/README.md

 Welcome to the Spark documentation!
 
-This readme will walk you through navigating and building the Spark documentation, which is included here with the Spark source code. You can also find documentation specific to release versions of Spark at http://spark.apache.org/documentation.html.
+This readme will walk you through navigating and building the Spark documentation, which is included
+here with the Spark source code. You can also find documentation specific to release versions of
+Spark at http://spark.apache.org/documentation.html.
 
-Read on to learn more about viewing documentation in plain text (i.e., markdown) or building the documentation yourself. Why build it yourself? So that you have the docs that corresponds to whichever version of Spark you currently have checked out of revision control.
+Read on to learn more about viewing documentation in plain text (i.e., markdown) or building the
+documentation yourself. Why build it yourself? So that you have the docs that corresponds to
+whichever version of Spark you currently have checked out of revision control.
 
 ## Generating the Documentation HTML
 
-We include the Spark documentation as part of the source (as opposed to using a hosted wiki, such as the github wiki, as the definitive documentation) to enable the documentation to evolve along with the source code and be captured by revision control (currently git). This way the code automatically includes the version of the documentation that is relevant regardless of which version or release you have checked out or downloaded.
+We include the Spark documentation as part of the source (as opposed to using a hosted wiki, such as
+the github wiki, as the definitive documentation) to enable the documentation to evolve along with
+the source code and be captured by revision control (currently git). This way the code automatically
+includes the version of the documentation that is relevant regardless of which version or release
+you have checked out or downloaded.
 
-In this directory you will find textfiles formatted using Markdown, with an ".md" suffix. You can read those text files directly if you want. Start with index.md.
+In this directory you will find textfiles formatted using Markdown, with an ".md" suffix. You can
+read those text files directly if you want. Start with index.md.
 
-The markdown code can be compiled to HTML using the 
-[Jekyll tool](http://jekyllrb.com).
+The markdown code can be compiled to HTML using the [Jekyll tool](http://jekyllrb.com).
 To use the `jekyll` command, you will need to have Jekyll installed. 
 The easiest way to do this is via a Ruby Gem, see the 
 [jekyll installation instructions](http://jekyllrb.com/docs/installation).
 If not already installed, you need to install `kramdown` with `sudo gem install kramdown`.
-Execute `jekyll` from the `docs/` directory. Compiling the site with Jekyll will create a directory called
-`_site` containing index.html as well as the rest of the compiled files.
+Execute `jekyll` from the `docs/` directory. Compiling the site with Jekyll will create a directory
+called `_site` containing index.html as well as the rest of the compiled files.
 
 You can modify the default Jekyll build as follows:
 
@@ -30,9 +38,11 @@ You can modify the default Jekyll build as follows:
 
 ## Pygments
 
-We also use pygments (http://pygments.org) for syntax highlighting in documentation markdown pages, so you will also need to install that (it requires Python) by running `sudo easy_install Pygments`.
+We also use pygments (http://pygments.org) for syntax highlighting in documentation markdown pages,
+so you will also need to install that (it requires Python) by running `sudo easy_install Pygments`.
 
-To mark a block of code in your markdown to be syntax highlighted by jekyll during the compile phase, use the following sytax:
+To mark a block of code in your markdown to be syntax highlighted by jekyll during the compile
+phase, use the following sytax:
 
     {% highlight scala %}
     // Your scala code goes here, you can replace scala with many other
@@ -43,8 +53,15 @@ To mark a block of code in your markdown to be syntax highlighted by jekyll duri
 
 You can build just the Spark scaladoc by running `sbt/sbt doc` from the SPARK_PROJECT_ROOT directory.
 
-Similarly, you can build just the PySpark epydoc by running `epydoc --config epydoc.conf` from the SPARK_PROJECT_ROOT/pyspark directory. Documentation is only generated for classes that are listed as public in `__init__.py`.
+Similarly, you can build just the PySpark epydoc by running `epydoc --config epydoc.conf` from the
+SPARK_PROJECT_ROOT/pyspark directory. Documentation is only generated for classes that are listed as
+public in `__init__.py`.
 
-When you run `jekyll` in the `docs` directory, it will also copy over the scaladoc for the various Spark subprojects into the `docs` directory (and then also into the `_site` directory). We use a jekyll plugin to run `sbt/sbt doc` before building the site so if you haven't run it (recently) it may take some time as it generates all of the scaladoc.  The jekyll plugin also generates the PySpark docs using [epydoc](http://epydoc.sourceforge.net/).
+When you run `jekyll` in the `docs` directory, it will also copy over the scaladoc for the various
+Spark subprojects into the `docs` directory (and then also into the `_site` directory). We use a
+jekyll plugin to run `sbt/sbt doc` before building the site so if you haven't run it (recently) it
+may take some time as it generates all of the scaladoc.  The jekyll plugin also generates the
+PySpark docs using [epydoc](http://epydoc.sourceforge.net/).
 
-NOTE: To skip the step of building and copying over the Scala and Python API docs, run `SKIP_API=1 jekyll`.
+NOTE: To skip the step of building and copying over the Scala and Python API docs, run `SKIP_API=1
+jekyll`.