Master Key multi-fix
by Tungstwenty


Fixes a few vulnerabilities that exist on the APK parsing code
that allow signed files to be tampered with.
One of these (bug 8219321) is known as the "Master Key" vulnerability, and can be found
in several places including this one: http://forum.xda-developers.com/showthread.php?t=2359943
Another one (bug 9695860) is also related with Zip (or APK) files parsing and although it's been
fixed by Google on the codebase (https://android.googlesource.com/platform/libcore/+/9edf43dfcc35c761d97eb9156ac4254152ddbc55),
it's likely to take even longer to reach the stock roms (if ever).
After the initial disclosure and release of these fixes, additional flaws of a similar nature
were found on the same Zip routines by several different folks independently, including myself,
and only made public and fixed during the release of Android 4.4 source code. The most relevant of those is bug 9950697.
These are also addressed by this module.

Follow this thread for additional info: http://forum.xda-developers.com/showthread.php?t=2365294

This project uses:
- Xposed framework, by rovo89
- Original code snippets from AOSP
- Icons generated with Android Asset Studio: http://android-ui-utils.googlecode.com/hg/asset-studio/dist/index.html