Update language.lua

The list of languages is updated. So now all the translations at least partially present in Transifex are selectable.
add android build target
use mupdf to handle zipped image files
initial commit for android port of koreader
This PR just shows how far we have went to
the android port. There is still a few steps before a running
android port.
Merge pull request #591 from chrox/master

initial commit for android port of koreader