Start of atmega32u4 port
Change register definitions for atmega32u4 serial comms
Change debug LED definition to match adafruit board
Add initial USB serial support.

Using the teensy board usb_serial example code from pjrc.com. This has a
smaller footprint than LUFA for simple serial I/O (may still migrate to
the LUFA libraries at a later stage).
USB bugfixes for successful comms
Move buttons from (non-existant) PC0-PC3 to PF4-PF7.
Enable serial debug output on PD3
Servo control updates

Servo output signal (OC1A) moved to PB5. Timer1 values changed
to reflect the new CPU speed of 16MHz
Merge branch 'master' into atmega32u4
Add 100ms timeout to USB read operation
Only send a response packet to GC after a valid control message.
Make resistance calculation a compile time option.

New constant 'LOOKUP_TABLE' enables the use of the lookup table, else
resistance will be calculated using equation from curve fitting.
Initial IDE settings to support LUFA library
Inital port to LUFA USB library

The LUFA library supports multiple endpoints. We should be able to use one
CDC-ACM port for the GoldenCheetah communication, with a second CDC-ACM
port for debug output.
Add the LUFA (130303) library files

Have removed a number of unused library files from the project folders. This
makes no difference to the generated code size, is just an attempt to avoid
bloating the repository with unecessary files (for other platforms etc).
Port serial debug output to second CDC-ACM endpoint

Use the second CDC-ACM interface for the debug output when built with
debug support. The USART functionality has been removed.
Merge branch 'atmega32u4'

Migration from ATmega168 to ATmega32U4 USB device. Using pjrc usb_serial
library for CDC-ACM virtual serial support.
Merge branch 'lufa'

Migration from pjrc usb_serial to LUFA USB library. This provides
additional flexibility for multiple endpoints (useful for debug
output).