Mburton/exp/annotationprocessor nonsilver

Better annotationprocessing support than https://github.com/roboguice/roboguice/pull/181

Need to verify that the performance improvement is the same as the other PR, but in theory it should be roughly the same.

Unlike https://github.com/roboguice/roboguice/pull/181 , this PR requires no or almost no changes to your app to use.

For apps that use injection in libraries, I'm not totally happy with the solution I came up with to enable multiple annotation databases.  Open to better ideas.

Also, some of this PR could use some cleanup.