[Screeninvader] Screeninvader License

[Amir Hassan]

Currently the Screeninvader is licensed GPL2 or later. I don't think GPL2  
is a wise choice considering the use on embedded systems. Now we still  
have the chance to change it!
I like the idea of AGPL3 (http://www.gnu.org/licenses/agpl-3.0.html) but  
need your opinons.

Furthermore we should address the problem of future license changes. will  
e.g. AGPL3 protect the screeninvader forever or will future developements  
require a new license? Anyway, this is how openscad is solving the license  
change problem:  
https://github.com/openscad/openscad/blob/master/doc/contributor_copyright.txt.
do we want something similar?

Please note, that i can't change the license without your permission  
unless i rewrite contributions myself. So please state your opinons on  
this very important matters.

greets,
amir