Update man pages with Mitaka version and dates
Update man pages with Mitaka version and dates

The keystone-manage listed out-dated version and date. This patch
bumps the version to 9.0.0 and the release date of 4-7-16 according
to: http://docs.openstack.org/releases/schedules/mitaka.html

Note: keystone-all was untouched since it's being removed under the
      eventlet deprecation.

Change-Id: I2e9de4ca1d19d5ee62b3c761bea46d6d61445fd6

klmitch/keystone,dims/keystone,rajalokan/keystone,rajalokan/keystone,mahak/keystone,himanshu-setia/keystone,ilay09/keystone,klmitch/keystone,openstack/keystone,openstack/keystone,himanshu-setia/keystone,dims/keystone,mahak/keystone,rajalokan/keystone,ilay09/keystone,ilay09/keystone,cernops/keystone,cernops/keystone,mahak/keystone,openstack/keystone