Update Textmate / Sublime's syntax highlighting for Dart. Removed `source` and `resource` keywords, removed need for `#` before `library` and `import`, added the `part` and `part of` keywords, changed so that raw strings start with `r` instead of `@`.
Merge remote-tracking branch 'upstream/master'
Fixed the show/hide/as highlighting glitch
Merge pull request #3 from timothyarmstrong/master

Update Sublime / Textmate syntax highlighting.