Add support for strikethroughs (~~)
Don't italicize part of words with GFM
Add support for fenced code blocks
Add tests for autolinking
Add support for www. autolinks
Change span parsing to base text on element ranges
Add support for autolinking URLs
Add support for autolinking email addresses
Fix autolink issue inside normal links
Fix handling of autolink email addresses
Change the new API to take a set of extensions
Expand underscores extension to cover strong too
Rename test sections using extension options
Merge branch 'master' into github-flavored-markdown

Conflicts:
	Source/MMParser.m
Add support for hard newlines
Improve handling of emphasis with word boundaries
Merge branch 'master' into github-flavored-markdown
Fix indentation issues (Thanks Xcode!)
Fix more nested emphasis cases
Add a WWW autolinking test