Add new TableOfContents Page variable (Markdown only)

Added TableOfContents field to hugolib.Page struct.  New function
getTableOfContents is used in convertMarkdown to set the TableOfContents
field.

Added new test file hugolib/page_toc_test.go with a simple test of the
new functionality.

Conflicts:
	hugolib/page.go
Big refactor of pages code. Changed TOC code to only parse when actually used
fixing 178.
Don’t render short codes on summary twice
Moved TOC test into page_test. Some general page_test cleanup.
Continue with TOC integration and page refactor. Updated a few tests to match new generated output.
Adding support for boolean params
Using table of contents within the documentation.
Add text transformation template functions.
Fix panic with HTTP serve initialization problems.
gofmt all go code
Add back blackfriday extensions during Markdown conversion

Modified markdownRender and markdownRenderWithTOC in hugolib/page.go to
use the same flags and extensions as were previously used when we simply
called blackfriday.MarkdownCommon to convert Markdown to HTML.  These
flags/extensions were dropped during the refactor that added the
`.TableOfContents` page variable, and caused features like Markdown
tables to no longer work.

Modified the expected output for TestTableOfContents in page_test.go,
apparently changing the flags/extensions caused an `&mdash;` to become
`&ndash;`.
Adding the ability to check the system limit on open files (important for watching large sites)
Automatically increase the process ulimit to maximum available.  fixes #168.
Fix permalink bug in uglyurls mode (refs #187).
Fix docs error with json comma
Add Ant Zucaro's showcase.

A photography-oriented blog using Foundation 5 by Zurb. Responsive
layout with padded large and full-width small views. A sample
"polaroid" shortcode is included for image showcases, as is a
"header" image directive in the frontmatter.
Add unicode support for aliases, indexes, urlize template filter.
Now aliases and indexes are not restricted ASCII letters and can include
any unicode letters.
Only change rLimit on OSX (where it is needed). Fixed #194
Updating Release Notes and Roadmap