A 2.3 version and performance improvements

A few things:

1. I rewrote the extension to load cursors from memory on Windows (rather than assembling a temporary CUR file to give to WinAPI), which makes it Really Fast (in case you are one of the people that wanted to change cursors every frame).
2. I added a GMS2.3 version, which is by all means identical to 2.2 one.
3. I updated the demo with controls to change framerate and an option to show the shadow cursor via cursor_sprite, which gives you a better perspective of lag between in-game drawing and a native cursor.
   You can now also hold 5 to see the cursor change colors and wobble around.

2.3 version has been uploaded to marketplace. 2.2 version is not currently updated on marketplace due to... whatever this is supposed to mean