ld lexer tidy, possibly break the world

This tidies the states in which ld lexer rules are enabled.
This change will quite likely trip over issues similar to those
mentioned in the new ldlex.l comments, so please test it out.

	* ldgram.y (wildcard_name): Remove now unnecessary components.
	* ldlex.l: Restrict many rules' states.  Remove -l expression
	state rule.  Comment on lookahead state madness and need for
	/DISCARD/ in expression state.