Multiple Dex Support - part 2

 - CS fixes
 - adds support for building multiple dex
 - prevents extra dex from being unknown and extra dex
 - adds unit-test
[dexlib2] allow disassemble of apks with non classes.dex files
Multiple Dex Support - part 3

 - dexlib2 handles non classes.dex
 - cleaned up functions
 - cs fixes