Ignore all *_tests.txt files
Reorganized fields in PinkySimContext

It was easier to move registers in and out of the context over the GDB
remote protocol if their order matched that for ARM registers in GDB
g/G packets.
Added a mockCommInitReceiveData() overload

This new overload accepts two receive packets so that a test can have
the code process one packet, see a pause in the data, and then process
a second packet.
Add gdbRemote module and tests

This module is able to send GDB remote commands to an ARM target to
set/getRegisters, write/readMemory, and single step it.