Fixing expression extractor & test

Noticed that this test was not failing when it should have been, there were two issues-
- The packages were not being specified for the test, so the expression extractor was skipping all Angular code.
- The source crawler was not including exported libraries which causes it to incorrectly skip chunks of Angular code.

End result is that the expression list being extracted was a fraction of what it should have been.

Closes #860
Fixing transformer tests to be passing

Getting a bunch of errors running run-tests.sh, these appear to be from: https://github.com/angular/angular.dart/commit/88593eec6499f93765980087fcdf59a242ec9334

Updates are primarily around modifying the test placeholder libs to match new names.
Also a number of the tests were refactored as part of the earlier referenced CL and the codepaths which was intended to be tested were no longer being excersized.

Closes #862