Preparation for Bower: move pub.dart to new package_mgmt/ dir
Better utilize existing and new methods in PubManager
Bug fix: custom Bower dependencies in New Project dialog were not processed
Bower support: download 1st level of dependencies from New Project dialog
Fixed wrong success/error message for Bower install (referred to "Pub get")
Merge remote-tracking branch 'refs/remotes/upstream/master' into bower-support-one-level-deps

Conflicts:
	ide/app/lib/package_mgmt/pub.dart
	ide/app/lib/services.dart
Resolved a merge conflict
Merge pull request #1503 from ussuri/bower-support-one-level-deps

Bower support 1.1: upon new project creation, download 1st level of dependencies from bower.json