Revert "New key press logic."

This reverts commit 884b475c72af12ec81ee97349db4409c9d574ed3.
Make control endpoint interrupted.

LUFA handles it internally.
Refactor timer code.
Add eventqueue.
Refactor eventqueue.
Use event queue for sending "normal" keycodes.
Rename event types.
Use a tailq instead of a ring buffer.
Add NumKeyPressed event.
Trigger NumKeyEvents.
Make tapkeys evented.
Further work on evented tapkeys.
Add timers.
Add poolallocator class.
Use new poolallocator for events.

Previously eventqueue had its own poolallocator implementation.