GitHub Flavored Markdown extensions

[bstefanescu]

GitHub Flavored Markdown extensions

1. Add GFM extensions not already covered by txtmark:

   • Strikethrough: Mistaken text.
   • URL auto-linking: http:// and https:// URLs are rendered as links. Example: http://example.com
   • Tables: see https://help.github.com/articles/github-flavored-markdown/

   See com.github.rjeschke.txtmark.GFMTest class for unit testing.

2. Bug fixing:
   StringIndexOutOfBoundsException exceptions are thrown when parsing the following content:

   • <\n lines. Example:

         <
         < some text
   

   The <\n line will trigger an exception

   • Broken link definitions (i.e. empty URLs) like [broken]: \n.

     Note that processing the line [broken]:\n does not throw an exception but if you add a space at the end of the line: [broken]: \n then processing will fail with a StringIndexOutOfBoundsException.

   Tests were added in Amps and angle encoding.text