Added latest changes but system_cache not working yet.

launch.dart: Make a check for running Chrome Apps, if a 'pubspec.yaml' file is selected then run tavern.

manifest.json: Renamed app to "Spark (with tavern)", changed the version number to 0.3 (to match tavern), added permission to access tapted's server process and added HTML5 unlimited filesystem storage capacity.

spark_polymer.html: Add the tavern JS to be able to send logging message to the tavern log window.

R=tapted@chromium.org

Review URL: https://codereview.appspot.com/54300045