APK format support

[thypon]

JAR contained in /system/framework are in APK format: they contains a classes.dex and resources. Could be possible to extend jardiff to support these files?

[JakeWharton]

The problem here is that you need to extract the dex and then either parse its classes and methods in the same format as javap or run a decompiler.

I'm not sure if something like that should be considered in scope. I'll accept a PR but I'm not going to implement it myself.