Early warning of Ogre, MyGUI and CEGUI updates in rawhide

[Bruno Wolff III]

I am finally starting work on getting Ogre 1.7 into rawhide. I will also
bump the related packages MyGUI and CEGUI to the latest version as well.
I'll be working on these locally so as not to make people rebuild
dependencies multiple times. Barring unexpected problems I should have this
ready before alpha (including dependent games that I can update).
I'll send out another warning shortly before pushing stuff to rawhide.