Implemented scrolling
Cleaned up implementation (scrolling)
Organized a bit for style
Temporary commit before merge to get deactivate (overriding activate)
Merge branch 'master' of https://github.com/dart-lang/spark into umop-outline-remember_position
Overriding activate and deactivate to store outline scroll position
Initial setup and implementation of SparkPreferences
Moved CachedPreference and BoolCachedPreference into preferences.dart
Review fixes
Review fixes
fix the new git tests
delete temp directory when the test finishes
Better handling of Untracked files.
Just recording the scroll position instead of listening for all scroll events
Merge pull request #1752 from dart-lang/umop-outline-remember_position

Outline: Remember position of current file
Resolved conflicts
Add git add command.
Add git add option to UI.
Add git add api to scm.dart.
Show git add only for scm projects.