Volume keys & file saving on Android

Thanks to a patch sent to me by @panreyes of PixJuegos, volume keys are now working. It's just three lines of code but it makes a huge difference in usability and frees you from having to code volume stuff by hand.

The same example I use for everything

Also, if you have been playing with previous versions of the Android builds, you'll probably have noticed that you cannot write data into the apk from BennuGD code. If you don't ask for the right permission in the AndroidManifest.xml you'll find that you cannot write to the SD Card (if the phone has an SD card and the user hasn't ejected it, that is) either.
The right place to put your game's files is at:
/data/data/[app_descriptor]/files
Right now [app_descriptor] is org.libsdl.app, so until I make it easy to change your app descriptor, you should write files to:
/data/data/org.libsdl.app/files

But we'll talk more about that later :)