Revert "Introduce nasty abstractions."

This reverts commit 1478a586a3fd24772c7c768fde9f570d197b0cd8.
Update README.md
Improve timer documentation.
Minor refacoring of usb code.
Move event dequeing to core.
Better debug messages.
Remove unused defines from config.h

Number of rows and collumns is detected automatically at compile time.
Update config for new wiring.
Call USB_Task() manually.
Use CDC usb class for console.