Moved '#define *DEBUG' defines to config.h, and document where first

found.

Document any '#ifdef' segments found in config.h

Remove gistold.c, since it was older copy of gist.c

Author: scrappy

src/backend/access/gist/gist.c

@@ -1196,7 +1196,6 @@ gistcentryinit(GISTSTATE *giststate, GISTENTRY *e, char *pr, Relation r,
 
 
 
-#define GISTDEBUG
 #ifdef GISTDEBUG
 
 extern char *text_range_out();