reimplement automatic copyright statement

[Peter Johansson]

needs #24

Copyright should be defines using alternative stats class (#24). When a author ha been owner of at least one line in at least one revision during the year, then the author has copyright of that file.

Remember, if author A is owner of a line in rev n, committed Dec 25 2007, and loses ownership of the line when author B commits a change of the file Jan 2 2008, then author A has copyright of the file for both 2007 and 2008.

ref #110

[Jari Häkkinen]

Are the A's and B's correct in the description? If not, then I suggest that B should only hold copyright for 2008 and the changed 2007 entry is lost without any copyright.

[Peter Johansson]

First of all, the description is rubbish. We should try to implement copyright update to follow GNU recommendations, in other words, you have copyright of a file for the year you have contributed to the file.

Losing copyright is another issue, which I thought we had discussed enough. Personally I think copyright is cumulative which means you can never lose your copyright. The reason is that it is cumbersome to differentiate between a complete rewrite of the line and an added space.