new Makefile hieracy

IMPORTANT: I renamed some build targets: "x86_client" isn't available anymore now it is called "cli"
so use "make cli" from now on.

I rewrote the makefiles. Now, you find all Makefiles in the main directory. The rules are still seperated into Makefile.library/*.firmware/... but now they are all included by the the "Makefile" which makes it easier to use intermediate files as dependecies.
All Makefiles offer a lot of potential for optimization, but I will not continue right now, since the most terrible issue with the dependencies is fixed now. I will continue to migrate the android_client to the new API and stabilize it (fritz reported crashes when returning from powersave mode)