Added timeout checks and retry functionality to control transaction
state machine. But some times the device just won't talk, so we flash
the fault LED slowly to give the user some clue about what happened.
- Unexpected second port-connected interrupt on cold boot with low-speed
device connected.
- Retry on failure to get device descriptor. (We still fail after three
attempts, but that is better than failing after the first one!)
Also changed eclipse project to use external builder.
Robert Fisk