Apply paxed's DEBUG patch to remove DEBUG/D_DEBUG.

Move debugging output into couple preprocessor defines, which
    are no-op without DEBUG.  To show debugging output from a
    certain source files, use sysconf:

    DEBUGFILES=dungeon.c questpgr.c

    Also fix couple debug lines which did not compile.

This also includes fixes due to Derek Ray to depugpline to work better
on other platforms.

src/sys.c

@@ -20,6 +20,7 @@ sys_early_init(){
 #else
 	sysopt.wizards = WIZARD_NAME;
 #endif
+	sysopt.debugfiles = NULL;
 	sysopt.shellers = NULL;
 	sysopt.maxplayers = 0;	/* XXX eventually replace MAX_NR_OF_PLAYERS */