Updated build files to reflect new dart binary locations
pub and dart2js support, plus some snippets
doc changes
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 `@`.
fix to the macos build file
Fixed the show/hide/as highlighting glitch
Adding support for multiline strings using single-quotes (multiline strings with double quotes were already supported.
Rebase with dartlang tm/sublime repo and cleanup

Performed a rebase with latest dartlang textmate/sublime repo (https://github.com/dart-lang/dart-textmate-sublime-bundle) to get latest syntax support and pub support plugin. This lead to dupes of some snippets and build system files - these were cleaned up.
Fixed up README and dart.sublime-settings
Remove pub_support.py plugin and update README

Removing pub_support plugin because I found that it causes slow down in ST2 startup performance. Also we have build script for pub support.