Bug fixes and add test.

1) Various bug fixes.
2) Add test for pack parsing.
indent fix.
Bug fixes and add test.

1) Various bug fixes.
2) Add test for pack parsing.
indent fix.
test tweaks
merge with remote.
Conflicts:
	ide/app/test/git_pack_test.dart
Catch exception in pack test.
fix object init  bug in pack.
Add apply delta to pack module.
Minor fix.
Merge pull request #189 from dart-lang/add_tests

Add pack objects tests