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. 
You could use this [status=error] to trigger your pulse animation.  It will not require adding/removing the pulse class.  You could then use `animation-iteration-count` to define how many times you want the animation to run.  3 times or so should be sufficient.