Align td and th with css instead of align property

When you align tables with css, <td align="..."> gets overridden.
Using inline styles keeps alignment no matter what CSS contains.
test rubinius on travis too

Run the tests for rubinius on travis too.
Mark any html_attributes has held by a renderer as used
Add redcarpet_ prefix for stack_* functions
Suppress compiler warnings
Ignored /tmp directory
Added support for org-table syntax

This just adds support for using a plus (+) as an intersection character
instead of requiring pipes (|). The emacs org-mode table syntax
automatically manages ascii tables, but uses pluses for line
intersections.
Removed and ignored Gemfile.lock

See http://yehudakatz.com/2010/12/16/clarifying-the-roles-of-the-gemspec-and-gemfile/
Fix #57 -- SmartyPants handling of single quotes.
Correct output when single quote is NOT being converted

E.g. if the original text is "test'test".
SmartyPants: Preserve single `backticks` in HTML

When SmartyPants is processing HTML (yes HTML, not Markdown), single
`backticks` should be left intact.  Previously they were being deleted.
Fix tests for libxml2 > 2.8
Fix compile error in C code
Added contributing file
Merge pull request #213 from brntbeer/contribution

Added contributing file
README language fixes

Fix some wording, grammar, etc.
Merge pull request #215 from mattr-/master

Trivial README Updates
Merge pull request #193 from rmm5t/ignore-tmp

Git ignore tmp directory
Merge pull request #172 from Gibheer/patch-1

Add Rubinius to the list of tested rubies
Merge pull request #194 from rmm5t/org-table-syntax

Add support for org-table syntax