[csw-maintainers] A copyright notice in the template

[Maciej (Matchek) Blizinski]

I've committed a change to the template: I added a short copyright
notice (GPLv2) and set the Id keyword so that the Makefile would
contain information about the current file revision:

https://sourceforge.net/apps/trac/gar/changeset/5704

Since it's the template, the impact would be only on new packages; a
package author could always remove the notice if they wanted.

What do you think of this change? Is it okay?

Maciej