When the timeout was too small, the main function would infinitely
loop around, restarting the board and waiting for the USB interface
to get configured. But since configuration seems to take more than
one second, it rarely succeeded.
Increasing the timeout makes the USB configuration finish in the
first try.
* Implemented configure, init, exit functions:
When a configuration is changed, interrupts for reset pins
should be disabled
* Moved variables shared between code files to simtrace.h
