Port git.js to dart APIs.

Exposes git.js APIS as dart APIs.
Don't instantiate git api.
add a test file for the git library
Merge pull request #25 from devoncarew/port_jsgit_to_dart

add a test file for the git library
Move git files to git/ folder

Move git.js => git/git.js
Move git.dart => lib/git.dart

Other minor fixes.
Resolve conflict

Conflicts:
	app/git.dart
Port git.js to dart APIs.

Exposes git.js APIS as dart APIs.
Don't instantiate git api.
add a test file for the git library
Move git files to git/ folder

Move git.js => git/git.js
Move git.dart => lib/git.dart

Other minor fixes.
Fix git include path in git_test.dart
Merge with remote branch and conflict resolution.
Merge pull request #24 from dart-lang/port_jsgit_to_dart

Port jsgit to dart