Configuration/Makefile cleanups

[Kaveh R. Ghazi]

 > From: "Zack Weinberg" <zackw@stanford.edu>
 > 
 > 	* configure.in: Use gcc_AC_PROG_YACC.  Look for flex in the
 > 	unified tree, then use AC_PROG_LEX.


I'm not sure we should use anything besides bison/flex.  Otherwise we
have the potential to cause subtle bugs which one cannot reproduce
because a different yacc/lex was used by the person sending the
bugreport.  We already have this somewhat due to possible bison/flex
version differences, but using entirely different programs makes it
more likely IMHO.

		--Kaveh
--
Kaveh R. Ghazi			Engagement Manager / Project Services
ghazi@caip.rutgers.edu		Qwest Internet Solutions