Use new Sokol logging mechanism

[edubart]

Sokol has a new style for logging stuff, would be nice if Sokol GP follows it.

[kkukshtel]

Does it currently route to the bound logger in the sg_desc? I'm binding the logging there to an external function so want to make sure I'm getting gp errors.

[edubart]

Does it currently route to the bound logger in the sg_desc? I'm binding the logging there to an external function so want to make sure I'm getting gp errors.

No, currently it follows the following logic:

#ifndef SOKOL_LOG
    #ifdef SOKOL_DEBUG
        #include <stdio.h>
        #define SOKOL_LOG(s) { SOKOL_ASSERT(s); puts(s); }
    #else
        #define SOKOL_LOG(s)
    #endif
#endif

But you can define SOKOL_LOG to override this behavior.