Include more debug for commands that sometimes return odd values
Add raw_write_mem32 command

Was having problems using read_debug_reg and write-debug_reg to write to
0x20000000, and getting status codes back that I obviously need to
decode better somehow.  _sometimes_ it had worked.  Some sort of access
protection to the running core?

adding teh write_mem32 command let me do a couple of manipulations on
the fly without having to get the full gdb up and running
swo decoder: Include signed output for 16/32 vals

Can't assume it's unsigned, so print out both, let the consumer sort it
out.