Added support for the embedded ruby language

Activated codemirrors native support for erb.
Corrected tab spacing
Fixed LanguageManager-test.js

Removed references to 'erb' and replaces with 'noSuchExt'.
Merge branch 'embedded-ruby-support' of https://github.com/olsgreen/brackets into pflynn/embedded-ruby-support

# By Oliver Green
# Via Oliver Green
* 'embedded-ruby-support' of https://github.com/olsgreen/brackets:
  Fixed LanguageManager-test.js
  Corrected tab spacing
  Added support for the embedded ruby language

Conflicts:
	src/extensions/default/JSLint/thirdparty/jslint
Map ERB forms of JS & SCSS to plain JS/SCSS.
Tweak ERB HTML definition: add block comments, more specific language id,
better list of file extensions.
Merge pull request #4979 from adobe/pflynn/embedded-ruby-support

Embedded Ruby support - redux