Optimizations for Android platform

[Shinmegumi]

I know a lot of this may have already been thought about, but I haven't had a chance to pull the APK code to take a look. Re-routing a few calls so a majority of the drawing can be offloaded to the GPU may help with performance. I know the GPU in most phones is either non-existant or not very powerful, but I think with the right work it could improve emulation a lot. I know this has probably been talked about and that this isn't anything new, but with the powerful cores in some of the new phones like the HTC One and S4, there may be an advantage to splitting up the work if it can be done.