Minor fixes: SPU, sys_mmapper, and cmd-line args.

* Some SPU instructions updated:
- Updated wrong instructions: SHLH, FRDS
- Added UNIMPLEMENTED warning to: HBR, HBRA, HBRR
* Updated sys_mmapper_allocate_memory declaration in SysCalls.h
* Added sceNp.cpp to project
* Added checkbox in the Settings menu for exiting RPCS3 when
sys_process_exit (SC_Process.cpp) is called. Unfortunately, due to some
problems, this checkbox doesn't have a real effect yet.