Optionally include prolog when writing out a Match

[jonas-lauber]

One should be able to specify if a prolog should be included when calling write(File file) or similar on a Match object.
Or a Match should have a prolog(boolean active) method to enable/disable the prolog when writing to file and the method $(File file) should init this flag if the file in parameter has a prolog.

[lukaseder]

You're right. I'll think about a reasonable solution to this...