Audio support

[dethrace-labs]

• Adds audio support, courtesy of miniaudio
• Fixes smack videos not clearing screen between frames (Playing Smacker videos does not clearing the screen correctly between frames #120)
• Fixes pedestrians running towards the car instead of away

[mackron]

FYI, I went ahead and gave this a quick try. Just a few things I found:

• In sound.c, the UsePathFileToDetermineIfFullInstallation() function uses fixed sized arrays of capacity 80 which is too small. My application path is this, and it just breaks with a stack corruption error: "C:\Program Files (x86)\GOG Galaxy\Games\Carmageddon Max Pack\CARSPLAT/DATA"
• Same as above, but in S3LoadSample() in s3audio.c.
• In audio.c and s3audio.c, the fopen(pThe_path, "r"); calls need to be changed to fopen(pThe_path, "rb"); (note the change from "r" to "rb").

After I fixed the above issues it seems to work quite nicely on Windows for me. Good work!

[dethrace-labs]

@mackron thanks for trying it out! I'll take care of increasing the path buffer size along with a comment explaining the change to the original code 👍