Fix SmartyPants handling of single quotes
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.
Remove unused C macros
Add option to ignore usual indented code blocks

Markdown converts text with four spaces at the front of each line to
code blocks. Of course we should support that, but when using fenced
code blocks, indented one can even be harmful. There should be a way to
turn them off.

This patch adds option to disable indented code blocks.
Adding a prettyprint class for google-code-prettify
Add optional underline support

This is `*italic*` and this is `_underline_` when enabled.
Ensure code spans put in emphasis work correctly

When putting code span into simple or double emphasis, we've got an
unexpected output. This commit fix this problem simply removing an
ignore statement about back ticks in the find_emph_char function
Ensure nested parenthesis are handled into links

Make sure that parenthesis inside the link's url are correctly parsed
Redcarpet considered the first ")" occurrence as the link's end so we
first count the number of open "(" and decrement this number each
time we found a ")".
Optional highlight support
Fix FTP uris identified as emails

Ensure FTP uris are correctly parsed and not considered as an email
address.
Make emphasis wrapped inside parenthesis parsed

Previously, when an emphasis was put inside parenthesis, the option
no_intra_emphasis return it as is. This commit fixes this issue. It
is a redundant issue in tutorials or in readme files.
Fix footnote parsing

Consecutive footnotes do not need to be surrounded by blank lines,
courtesy of @microjo. For example, this is now possible:

[^1]: footnote1
[^2]: footnote2
Output <hr/> for footnotes when using XHTML renderer
Allow to set a maximum rendering level for HTML_TOC

Allow the user to pass a `max_level` option when instantiating a new
HTML_TOC render object in order to limit the nesting level in the
generated table of content.
Set SD_AUTOLINK_SHORT_DOMAINS flag always on
Option to replace quotation marks with <q>
':' is now considered a trailing punctuation
find_block_tag: Use faster switch statement over an array lookup