Override MSDXImageTransform (IE8/9) gradient filter

Occurs when engine is mounted in the Public Website. Related:
https://github.com/moneyadviceservice/action_plans/issues/15
Add ns-engine namespace to allow body styles to be applied within an engine sandbox

See https://github.com/moneyadviceservice/action_plans/issues/13 for
more information.
Merge pull request #307 from moneyadviceservice/fix/engine-body-styles

Fix/engine body styles
Add jshint_ruby gem.

@jongilbraith
Very basic implementation of an asset pipeline JsHint processor.

Basic implementation nailed out while pairing with @pvcarrera.
Make jshint use the jshintrc.

Can also now use less convoluted sample code.
Remove test dependency on external jshintrc.
Simple rake task to run jshint on javascript assets.
Only lint js assets in app/assets.
Get rid of hacky stubbing of initialize.
Sort results by character as well as line.
Add list of known globals
CamelCase MAS.bootstrap.I18n_locale
Shorten long lines
Refactor new element construction

Easier to read but also shorter line length for jshint validation
Use singlequotes rather than doublequotes for strings
Add missing "use strict" to funcion definition
Rewrite translations files to be compliant with jshint
Remove unused function params
Use '()' when calling a constructor