check in android assets loading change, so it will not throw FileNotFoundException if the assets are not in the apk, instead it will try to load with the same path as a plain file
fix sound replay bugs, add dispatch-async for sound playing on ios
check in sound changes for iphone performance
remove systemsound code
Various optimizations in the sound class.

Not implemented methods and properties are marked as not-implemented.
Now sound data are loaded once and cached in memory for when an audio
  player will need it after. This should reduce spikes and improve perf.
After a sound has been played, Audio players is recycled for the next
  same sound instead of being disposed.
Both sound data and audio players are cached by URL.
Code is now more optimized related to removing audio players that are
  finished.
Changed events from iOS callbacks so they are dispatched at a safe point.
  This seems to have fixed random crashes with no callstack in the simulator.
Added a method to warm the sound cache to reduce synchronous loading of sounds.
Disabled the limiter on the max number of sounds played simultaneously.
  In our test case, we barely reach 10 sounds at the same time, so this
  was probably not the issue.
Added average N=10 frames in the profiler report.
Better caching system for Context3D
Merge pull request #304 from playscript/statge3dcache

Better caching system for Context3D
New file added to the list of source files for Make (fixes Jenkins build problem)
New file added to the list of source files for Make (fixes Jenkins build problem, _aot)
Fix broken mcs build
added null check for AppGetDelegateTypeForMethodCallback
Fixed android alpha texture by disabling caching
Made list of playing sounds more accurate.
  Added debugging features.
Fixed active texture caching on Android
Fixed Android build error.
Improvements in profiler history.
  Now in the history we store the number of calls on a given frame.
  A letter is added to the numbers to match the section.
  Fixed bug in history numbers not matching section order.
  Removed limit of 1000 frames displayed in history.
  Now we only print history in the file and not in the console log.
Added support for frame skipping in the profiler.
merge with latest playscript-mono
Merge branch 'android-assetsloading'