Install pkg-config files if and only if *the cmake host* is unix and not apple.
Install pkg-config files if and only if *the cmake host* is unix and not apple.

--HG--
branch : v0-8

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