r600g Todo List

I've just updated the R600Todo page, with some LLVM and Compute tasks.  I'll try to keep this page updated and add more tasks as I think of them.

These tasks are a great way to get started on GPU driver development, so if you are interested, pick a task and start hacking!  Also, let me know what you are working on so I can update the page.  If you have any questions about any of these stop by #radeon or #dri-devel on irc.freenode.net and ask.