Higher precission and monotonic timers

monotonic timers in platforms where is available (all except raspberry pi) and higher precision timers, mostly on windows where the precision was ms, now should be 1/100th of a ns. also sleeping should be more accurate, should solve:

http://forum.openframeworks.cc/t/emptyexample-running-at-50fps-in-release-mode/13731/10

and similar problems, we should probably enable the higher precision timing under windows in ofAppRunner:

```cpp
    #ifdef WIN32_HIGH_RES_TIMING
		timeBeginPeriod(1);		// ! experimental, sets high res time
								// you need to call timeEndPeriod.
								// if you quit the app other than "esc"
								// (ie, close the console, kill the process, etc)
								// at exit wont get called, and the time will
								// remain high res, that could mess things
								// up on your system.
								// info here:http://www.geisswerks.com/ryan/FAQS/timing.html
	#endif
```

since it seems to make a difference in the precision of the sleeping times