On some system it seems that the stack is quite small so now we heap
allocate the buffer instead. Also updated the docs and examples using
that instead of being on the stack. Bumped version to 0.2.4
Closes#8
* Removed hard coded global values for width, height, buffer - These are now tracked on a per window basis.
* Fixed multi-window support
* Various cleanup and fixes
* Added get_keys_pressed(KeyRepeat::Yes/No) in order for the user to
decide if repeat should be used or not
* added is_key_pressed(key, KeyRepeat::Yes/No)
* Added set_key_repeat_delay/rate in order to control the rate/delays of
keys