fix issue where generated xcodeproject added all headers as public except the last one in the list.
fix issue where generated xcodeproject added all headers as public except the last one in the list.

this bug would cause the resulting xcodeproject to fail to install last header file to the .framework bundles, making them unusable

this issue resulted in broken frameworks, all which missed at least one header file when installed.
this issue was caused by a misuse of set_target_properties , which was receiving an argument that
incorrectly separated source files.

--HG--
branch : v1-9

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