This is to become a GIL to BIL converter.

It uses a simple yacc and lex grammar to parse, and builds a tree.

Then it walks the tree calling do_node() for each node.
The provided do_node() writes BIL, but you could easily
write a do_node that would write UIL, UIMX, or any other
GUI-builder format.

Most of this program is still to be written, of course.
Lexing is done. 
Still need to:
	write an actual yacc grammar
	write code to store the tree
		walk the tree, emitting BIL
