Added an option enable/disable generation of the doc build target (enabled by default for retro-compatibility).
Added an option enable/disable generation of the doc build target (enabled by default for retro-compatibility).

--HG--
branch : v1-9

digimatic/ogre,digimatic/ogre,digimatic/ogre,digimatic/ogre,digimatic/ogre,digimatic/ogre,digimatic/ogre