2007-01-30 Paolo Bonzini <bonzini@gnu.org>

	* data/bison.m4 (b4_percent_define_flag_if): Don't treat 0 as false.
	Complain if the value does not match empty, "true" or "false".
	* data/c++.m4: Adjust default definitions of %define variables.
	* data/java.m4: Adjust default definitions of %define variables.
	* doc/bison.texinfo (Decl Summary): Adjust the %define entry according
	to above behavior.
	* tests/input.at (Boolean %define variables): Test new behavior.