Remove dependency on mask module

[bitcraft]

Removing this dependency will make it easier to support pygame forks without the mask module. Comments?

[mclaughlinconnor]

I found that by completely replacing the smart_convert function in util_pygame.py with code below:

tile = original.convert_alpha()
return tile

Allows me to remove the mask submodule altogether and even use Pygame_SDL2, though I can't get it to run properly on Android (See the issue renpy/rapt#5)

Correct me if I'm wrong but, is the entire smart_convert function only used to improve efficiency.
I tested this on a few games I found around the internet, and all seemed well.

[bitcraft]

You are correct, smart convert is only used to improve rendering speed by determining the optimal surface format. The mask module is used to determine if there are transparent pixels and can do that really quickly. A work around may be to use a slower method if mask is not available. Thanks for checking it out and testing.

[mclaughlinconnor]

No problem, all I did to start was hard code the px, the moved from there.

[bitcraft]

I've included a small check for the mask module and it should work with pygame_sdl2 now. It will simply convert_alpha the surface if it fails to get a mask.