Added bitmap persister classes and (empty) test classes
Added Javadoc, changed LruCache key to use Objects instead of Strings
Added support library dependency, fixed checkstyle violations
Added some more Javadoc and proper handling of CacheDuration.ALWAYS
Added author tag
Added tests for the two ObjectPersister classes
Added an InFileBitmapObjectPersister; changed around packages; added an optional FallbackPersister parameter to the InMemoryLRUObjectPersister to allow it to decorate other persisters, making a 2-level cache possible.
cleanup, fixing some tests
removed unused override
Merging LRU work from David and Mike
Add BitmapRequest and test