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.

include/global.h

@@ -11,6 +11,8 @@
 
 #define BETA		/* development or beta testing [MRS] */
 
+#define DEBUG
+
 /*
  * Files expected to exist in the playground directory.
  */

include/hack.h

@@ -11,9 +11,31 @@
 #include "config.h"
 #endif
 
-/*	For debugging beta code.	*/
-#ifdef BETA
-#define Dpline	pline
+#ifdef DEBUG
+/* due to strstr(), mon.c matches makemon.c */
+# define showdebug() (sysopt.debugfiles &&			\
+	    ((sysopt.debugfiles[0] == '*') ||			\
+	     (strstr( __FILE__ , sysopt.debugfiles))))
+
+/* GCC understands this syntax */
+# ifdef __GNUC__
+/* ... but whines about it anyway without these pragmas. */
+# pragma GCC diagnostic push
+# pragma GCC diagnostic ignored "-Wvariadic-macros"
+#  define debugpline(args...)                       \
+     do { if (showdebug()) pline( args ); } while(0);
+# pragma GCC diagnostic pop
+# endif
+
+/* and Visual Studio understands this one */
+# ifdef _MSC_VER
+#  define debugpline(...)                           \
+     do { if (showdebug()) pline(__VA_ARGS__); } while(0);
+# endif
+
+#else
+# define showdebug() (0)
+# define debugpline(...)
 #endif
 
 #define TELL		1

include/sys.h

@@ -15,6 +15,7 @@ struct sysopt {
 	char *recover;	/* how to run recover - may be overridden by win port */
 	char *wizards;
 	char *shellers;	/* like wizards, for ! command (-DSHELL) */
+	char *debugfiles; /* files to show debugplines in. '*' is all. */
 	int   maxplayers;
 		/* record file */
 	int persmax;