Always return a file descriptor in sceIoOpenAsync.

Fixes #646.
Show an FPS counter if ini option is true
Merge pull request #648 from unknownbrackets/io-minor

Always return a file descriptor in sceIoOpenAsync
Merge pull request #649 from unknownbrackets/display-multi

Implement sceDisplayWaitVblankStartMulti()
Show record high FPS
Merge pull request #650 from KentuckyCompass/fps_counter

Fps counter
Add very simple rapid fire for Windows keyboard.

Mostly to speed up debugging.
Move currentThread init to a better place.
Move running thread resched to __KernelNextThread.

Pretty sure this is needed, but apparently it breaks Sol Trigger.
Spend less time moving ts events in CoreTiming.
Wake delayed threads directly, rather than looping.

This saves ~1% during fast forward on a release build.
Add a std::vector wrapper to do remove/pop/push.

It showed up in a profile after all.  Cut down more than 1%.
Minor perf gain in __KernelNextThread.

Just like .1% but was hoping Mr. Optimizer would do this for me.