Un-revert gentoo changes and fix licensng issues

My original pull request included a GPLv2 license statement in the Gentoo WALA init script, which made it incompatible with WALA's Apache 2.0 license so it was reverted. This pull request includes an un-revert of the Gentoo bits as well as a removal of the copyright and licensing statement in the submitted code so that it should no longer conflict and will fall under the umbrella of WALA's Apache 2.0 license.