Starting an angular application from a library is not supported

[vicb]

/ref https://github.com/vsavkin/angulardart-sample-app/pull/20

The sample application from @vsavkin is using an uncommon pattern:

• The angular application is started from a library,
• The application code calls that library to start the angular application

A user has reported an error with the latest version of angular. I've added a detailed description of the error in the initial bug report but the short version is that the library code, where the angular application is started is not transformed resulting in a dynamic version of the Application being used.

Do we want add support for this pattern to the transformer ?

Some thoughts:

• We might scan the libs only if the application_factory.dart is not imported is the application entry point,
• If we don't want to support this pattern we should generate an error when no angular application is created in the app code.

[mhevery]

Low priority. We may chose to support it later.