* license of the project is GPLv3 now

* This still refers to a wave file that shouldn't be checked in.

* Allows one-time analysis of arrays or short streams.
* Transformation on real-time streams
* Magnitude and phase extraction
* Windowing (only Hamming for the time being).

* Just like the original LuaJIT interpreter, this will use a hook to automatically
  raise an error from Lua code.
* Unfortunately, as long as Jit compilation is enabled, this cannot reliably work.
  Therefore we still set an `interrupted` flag that must be
  polled from tight loops.
* Instead of polling via applause_push_sample() which gave interruption-support only
  to Stream:play(), we now have a separate checkint() function.
* checkint() should be manually added to all tight loops.
* Stream:foreach() and everthing based on it is now also supporting interruptions
  (via checkint()).
* This internally works via applause_is_interrupted().
  A C function was exposed only because LuaJIT does not support volatile-qualifiers and
  would optimize away reads to the interrupted-flag.
  As a side effect, we can also reset the hook.
* Flags set in signal handlers should be `volatile`.
* Added likely() and unlikely() macros to C code.
* Updated sample.ipynb Jupyter notebook: Everything important is now supported, albeit
  requiring custom ILua patches.

* This works for relative, absolute and keyboard devices
* devices can be grabbed, so they do not interfere with the rest of the system