Big update

+ Added One-Trigger-Timers
+ Added Character/Back-/Forecolor Lock
+ Added subrect image check to prevent parent image freeing
+ Added mouse key/move events
+ Added asciiClipRect
+ Added sample shell
* Improved emscripten perfomance up to about 1/7 the time
* Changed standard types to ascii specific typedefs
* Restructured API functions
* Changed coordinate type from uint8 to int32
* Changed standard colors to clear character
- Fixed subrect image bug
- Removed asciiDrawCharColored as this is basically asciiDrawCharacter