intial implementation of markers
add marker events
turn on code ace completion
Merge branch 'master' into work
added tests
Merge branch 'master' into work
fix nits
addressed comments
Minor naming fix in library names.
Merge branch 'dev' of http://github.com/camfitz/spark into dev
Merge pull request #563 from camfitz/dev

Fixed library names of git commands.
Merge pull request #561 from dart-lang/markers

Add makers to workspace
Merge pull request #553 from ussuri/polymer-switchover

Polymer switchover
Update pubspec.yaml

TBR - cap the version of grinder at <0.5.0, in order to not pick up a breaking change
Merge branch 'master' into devoncarew_code_completion
enable ace's code completion
ws nit
Merge pull request #568 from dart-lang/devoncarew_code_completion

Devoncarew code completion
Set window title to Spark in Polymer UI (was SparkPolymer)
Freeze the default UI to be Polymer + hide "Switch UI" menu by default

1) The last used UI was persisted before. Now the default UI can be enforced locally by modifying the value of DEFAULT_SKIN_ in background.js.
2) The "Switch UI" can be temporarily brought back by modifying the value of CAN_SWITCH_SKINS_ in background.js.