Register icon for .dart files.
Added RX.
Add stream for Dart project change notifications.
Added DartAnalysis package.
Create wrapped around external DartAnalysisService.
Add new error handling via Google's service.
Removed old external DartAnalyzer code.

This has been replaced with calls in to Google's Dart Analysis service,
Update the DartAnalysis service and handle errors better.
Handle updating content as the user types with a 500ms throttle.
Added TODOs.