Experimental usb support
Finished USB support for attiny85
Added todo regarding USB
us not ms
Some major changes

Reduced base clock to 16.5MHz
Added auto tune rutines for OSCCAL calibration
Added key release event after each character
Added leading 0's to the card number
Delay changes (needs more work)
Removed tune target from Makefile (as its not needed anymore)
Merge pull request #2 from NFQ-Makers/micro_version

Micro version