license: xlators/protocol/server dual license GPLv2 and LGPLv3+

cherry-pick from:
 refs/changes/16/4816/1; http://review.gluster.org/#/c/4816/

BUG: 951551
Change-Id: I3de5bd86d4238a60a0a85ba2e15d9c131969b210
Signed-off-by: Kaleb S. KEITHLEY <kkeithle@redhat.com>
Reviewed-on: http://review.gluster.org/4817
Reviewed-by: Jeff Darcy <jdarcy@redhat.com>
Tested-by: Gluster Build System <jenkins@build.gluster.com>