Add an include statement to Makefile.gtk that imports if present a

file called Makefile.local. This means that if you're compiling on a
platform that needs COMPAT definitions, you can put them in a local
file and not have to type them on the command line every time.

[originally from svn r8045]

mkfiles.pl

@@ -931,6 +931,8 @@ if (defined $makefiles{'gtk'}) {
     "# to 1.2 if it isn't found.\n".
     "GTK_CONFIG = sh -c 'pkg-config gtk+-2.0 \$\$0 2>/dev/null || gtk-config \$\$0'\n".
     "\n".
+    "-include Makefile.local\n".
+    "\n".
     &splitline("CFLAGS = -O2 -Wall -Werror -g " .
 	       (join " ", map {"-I$dirpfx$_"} @srcdirs) .
 	       " `\$(GTK_CONFIG) --cflags`").