alpha3

[current version]
2.1 alpha3 (21A03)
[changelog]
alpha1:Initial alpha release of UVEngine 2.1.
alpha2:Fix the size of the game window.
alpha3:Partially fix the touchpoint problem.
alpha4 (not published):Added temporary hack to fix the touchpoint
problem on 800*480 devices (other resolutions not fixed).
[buglist]
Touchpoint still buggy.
Unable to recover from background currently.