* SUPPORT, LICENSE: New files.
* Numerous files touched as part of merging the 4.5 branch
onto the mainline development trunk and ensuring that the
script that cuts snapshots and releases works on the documentation.
match the one in CPU.H. Added spurious_handler and exceptions_in_RAM items.
Added definations for clicks_per_usec, spurious_handler,exceptions_in_RAM,
serial_external_clock, serial_cts_rts, timer_average_overhead, and
timer_least_valid.