dyncom: Implement UXTB16/UXTAB16

Frameskip

armemu: Simplify some instructions.

Qt: Citra crashes if disassembler pause button is pressed while no game is running. #172

vfp: Actually make the code somewhat readable

New Handle manager

Implement PKHBT and PKHTB on dyncom, fix on armemu

dyncom: Implement USAD8/USADA8

armemu: Fix underflows in USAD8/USADA8

This handle manager more closely mirrors the behaviour of the CTR-OS
one. In addition object ref-counts and support for DuplicateHandle have
been added.

Note that support for DuplicateHandle is still experimental, since parts
of the kernel still use Handles internally, which will likely cause
troubles if two different handles to the same object are used to e.g.
wait on a synchronization primitive.

Initially reported by xdec.

Implement the rest of the UQ* ops.

dyncom: Implement UHADD8, UHADD16, UHSUB8, UHSUB16, UHASX, and UHSAX

armemu: Implement UHADD8, UHADD16, UHSUB8, UHSUB16, UHASX, and UHSAX

Fix visual studio ambiguous symbol error

Fixup gsp synch

More services & small clean ups

- Also a few cleanups.