Got to build with DEBUG constant defined.

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>