Add a subject for Guava's Optional.
Add hasValue() to OptionalSubject
Fix error names a bit.
Fix up some javadocs.
Fix copyrights and generics in TestVerb.
Improve the messaging on a null-subject passed in to OptionalSubject
Add OptionalSubject to GWT
fix imports.
formatting fix.
Merge pull request #87 from cgruber/optional

Add a subject for Guava's Optional.