added the ability to test the chrome+dart2js version of the app (as well as the dartium version)
style nit
Add git objectstore.

Also adds utility class file_operations.
Remove extra whitespaces.
added --chrome-stable and --chrome-dev flags
upgrade ace
ws change in logging output for test runner
Fixed comments by Devon.
return fix.
Moved the entire implementation under ide/, further to be split into ide and ui_lib.