stub out String.prototype.clean if it doesnt exist
bump package.json
update documentation
Merge tag '0.5.0'

elease 0.5.0

Deprecated
 - String.clean is now deprecated, bad idea, stubbed out for now. Soon to be removed.

Added
 - Added ability to instantiate new instances of the filter with the Factory property
 - Added ability to add new words to the filter list with the addWords method (thanks @petreboy14)
 - Added ability to override the default placeHolder when using a custom filter