rename ExprBFunc to ExprC

	modified:   Decode.hs
	modified:   Evaluation.hs
	modified:   Interpreter.hs
	modified:   Parser.hs
add Compiler, generate haskell code

The generated code can only be compiled unoptimized.

	new file:   Compiler.hs
	modified:   Makefile
	modified:   Parser.hs