Add folders to git index.
Create and  update folder status.
Fetch and folder status from scm optimized.
Show folder status in files view.
show git add option for folder.
Merge branch 'master' into fix_bug_in_index
don't track .git files.
Rename updateIndexFor entry in git index.
indents and rename in commit.
Fix bugs in git status.
percolate change to ancestor folders for git status.
indent and cleanup.
Merge branch 'master' into add_status
comments.
Merge branch 'master' into add_status

Conflicts:
	ide/app/spark.dart
Merge pull request #2166 from dart-lang/add_status_for_folders

Add status for folders