Merge branch 'release-0.15'
Bump version to 0.15
Merge branch 'master' into debian
Bump version to 0.15-1~wheezy

Signed-off-by: Christos Stavrakakis <cstavr@grnet.gr>
Merge branch 'debian' into debian-develop

* debian:
  Bump version to 0.15-1~wheezy
  Bump version to 0.15

Conflicts:
	version: take version of debian-develop
Switch license to GPLv3

According to the decision of the GRNET Board of Directors,
switch license to GPLv3.

This commit updates Debian's copyright notice.