Adds wxCmdLineParser to Rpcs3App

Adds a command line parser to Rpcs3App with the option to run in a test
mode. In test mode, a specified (S)ELF file is executed and rpcs3
terminates after it's execution, allowing to run rpcs3 in a batch mode
for automatic testing.
First stab at a unittest

A unittest for rpcs3 written in python, that uses ps3autotests to run
automated tests for all ps3autotests with a single `*.elf` and a
corresponding `*.expected`.