Add a lint indicator that replaces Brackets lint indicator

Removes default Brackets lint status indicator.
Replaces the `errorIndicator` with this `lintIndicator`.

See #61 for more detail on the reasons for this. 
Awesome, this looks much better.  We should also have the require statements follow the same comma separated definitions pattern as brackets.getModule.  I see you are trying to keep variables that are related, but that can also fragment the code making it a bit harder to follow.