Bug 924615 - Move JarMaker.py into mozbuild; r=mshal

--HG--
rename : config/JarMaker.py => python/mozbuild/mozbuild/jar.py
rename : config/tests/unit-JarMaker.py => python/mozbuild/mozbuild/test/test_jarmaker.py
Bug 924617 - Part 1: Properly format jar.py; r=mshal