Steps towards a working PlayStation Mobile implementation of Effect

These are the commits I've made to get Effect closer to working on PlayStation Mobile. I am pretty sure they break BasicEffect, but I can't be sure, because it's next to impossible to get any of the samples to run on PSM for me, either against trunk or against my branch.

These changes (along with the other changes from my branch) were sufficient, however, to port my XNA Effect-based rendering stack over to PSM with only minor changes, so I think they're an improvement. It should be possible to make BasicEffect work again if someone can point me towards a sample that uses it and should work on PSM.