Double slash comment support

Kindly contributed by @kerma. Thanks!

Data source support

@Jonnymcc was kind enough to add support for data sources.

Provisioner block support

Merge pull request #13 from ApsOps/add-provisioner-snippet

Add provisioner block snippet

Support BracketMatcher

Merge pull request #12 from Jonnymcc/master

Support BracketHighlighter

Snippets

Merge pull request #10 from maplebed/master

A couple more snippets and README changes.

Support for block comments

Merge pull request #8 from bigkraig/master

Support for block comments with /* */