Got to build with DEBUG constant defined.

PCB was not building when DEBUG was defined; the follownig changes
got it to build.  In boolean.c disabled compilation of unused
functions by changing "#ifdef DEBUG"s to "#ifdef DEBUG_UNUSED"s.
In edif.y fixed forward reference problem by moving definitions of
"Parser state variables" to just before the function referencing
them; also updated some old defined constant names.  In gcode.c
added "#include <locale.h>".

Signed-off-by: Bert Timmerman <bert.timmerman@xs4all.nl>