[MP] Fix reading 4 byte UTF-8 text input
[SP] Fix reading 4 byte UTF-8 text input
[SP] Minor sdl_input.cpp cleanup
[MP] Don't add duplicate resolutions to r_availableModes
SDL can give the same resolution with different refresh rates.
The refresh rate isn't used, so only add resolution to mode list once.
[SP] Don't add duplicate resolutions to r_availableModes
SDL can give the same resolution with different refresh rates.
The refresh rate isn't used, so only add resolution to mode list once.
[SP] Minor sdl_glimp.cpp cleanup
[MP] Clear window buffer when it's created
When starting the game in windowed mode, the window buffer used whatever
was on the screen before running the game. Kind of like you could see
through the window, but it doesn't update what happens behind it.

It makes it look like something is broken or non-responsive.

So clear the window opengl buffer to black.

Credit to theinvsblman for the code.
[SP] Clear window buffer when it's created
When starting the game in windowed mode, the window buffer used whatever
was on the screen before running the game. Kind of like you could see
through the window, but it doesn't update what happens behind it.

It makes it look like something is broken or non-responsive.

So clear the window opengl buffer to black.

Credit to theinvsblman for the code.
[SP] Fix SDL video driver checks.