Correct CMakeLists.txt with adding inclusion of OGRE_INCLUDE_DIRS for shiny.OgrePlatform

If for example root directory of some project contains in CMakeLists.txt inclusion of `OGRE_INCLUDE_DIRS` and only then includes `shiny` this is not required. But if it is not, compling `shiny` will popup errors complaining it can't find Ogre header files. My knowledge of CMake is poor, did I done it right?

Same need to be done for `boost`, I don't have time currently, maybe later.