update to build a wider range of recent NDKs (use gcc 4.6)
try new tricks for getting sdcard path on Android 4.3/4.4 and newer

They've messed up the sdcard path even more since 4.2.2, we need even more
silly tricks!

fixes #66
fixes #82
fixes #81

Conflicts:

	src/info/guardianproject/lildebi/NativeHelper.java
in Terminal Emulator is installed, add menu item to launch Debian shell

Thanks to Alexander-- for the key inspiration and research.

closes #76