Bump minimum required CMake version to 2.8.12.
Bump minimum required CMake version to 2.8.12.

--HG--
branch : v0-8

cbeck88/cegui-mirror-two,cbeck88/cegui-mirror-two,cbeck88/cegui-mirror-two,cbeck88/cegui-mirror-two,cbeck88/cegui-mirror-two