2009-09-05	Timo Bingmann

	* Two small fix-up lines to get it working with bison-2.4.1. Added
	one standard header include and making CalcNode a opaque class
	pointer in %union due to changed include file order.

	* Correcting associativity of the power operator: right.

2008-10-23	Timo Bingmann

	* FlexLexer.h, scanner.ll: Corrected a very subtle bug with the
	newly introduced virtual yywrap() function in the FlexLexer
	class. Depending on how the header was included, the class
	contained the virtual yywrap() function or not. These differing
	class declarations lead to very strange NULL pointer exceptions,
	because the different compiled objects assume different class
	memory layouts. Ultimately the exprtest program always segfaulted.

2008-08-03	Timo Bingmann

	* scanner.ll, y.tab.h: Fixing compilation problem which was
	reported to happen when no %union directive is used: in this case
	the include headers order is changed around by bison and breaks
	compilation. This was fixed by never including parser.h directly,
	but always using scanner.h.

	* FlexLexer.h: updated file to work with new flex version
	2.5.35. The new version adds a virtual function yywrap() to the
	yyFlexLexer class. This function is automatically defined in any
	lexer source file generated by flex. However because I copied
	FlexLexer.h from an older flex distribution, the function
	definition throws a "no member function" compiler error.