some of the mess in here really bothers me

(cherry-picking this commit of mine from next since it only fixes a small oversight with compiling and adds a comment)

the screen texture does not need an alpha channel.
the fact that it had one made OGL copy the topmost pixel of the screen texture's alpha channel.
which, naturally results in the screen becoming partially transparent and letting you see the working texture in the background.

g_game.c: In function 'G_CheckDemoStatus':
g_game.c:5588:22: warning: logical not is only applied to the left hand side of comparison [-Wlogical-not-parentheses]
   if (!modeattacking == ATTACKING_RECORD)
                      ^