Multimedia Submission

***This pull request probably contains many deletions because I cleaned up the previous (non-polymorphic) detail views through deletion***

Multimedia can now be submitted on the Android side. Waiting for paperclip and S3 to be accept files so that we can start debugging it.

To do this I needed to completely revamp the PostSpark APIHandler, including implementing a new Apache library. If you download the code it may have trouble compiling/running because Eclipse hasn't been configured with the new library. It'll be in the libs/ folder, you should be able to just add it through the build path. 

I also added a couple nice pictures because the app is pretty bland.