Don't allow extend votes when there is no time limit.

Otherwise the game time could be set to 10 minutes – and if 10 minutes have
already elapsed since start, game over.
Avoid localisation issues with md5sum in the download script.

(Fixes issue 150)
Use ambient and directional light for /r_rimLighting mode
Have /setlevel use admin_find_admin().
Bump the buffer size for the GL info text to 32000 bytes.
Clean up admin print, fixing remaining quoting issues.