Add cycle detection using the problem detector, plus test.
Return early on a graph validation failure, but continue to process other modules.
Make the verification test slightly saner.
Merge pull request #163 from cgruber/compiletimecheckcirculardeps

Add cycle detection at compile-time using the problem detector, plus test.
Reject @Provides methods with 'throws' clause, at compile time.

Any throws clause is rejected, even one documenting a RuntimeException or
Error.

Fixes #160
Merge pull request #162 from tbroyer/provides-methods-with-throws-clause

Reject @Provides methods with 'throws' clause, at compile time.
Complaining about non-static inner class injection closes #68
Merge pull request #164 from square/kiran/inner-classes

Complaining about non-static inner class injection