Removed Rift Creation and Unused Settings

Removed the rift creation code from the Rift Blade and removed unused
settings from DDProperties. Specifically, the rift creation flag for the
Rift Blade, since that's getting removed, and the RiftSpreadModified,
which hasn't been referenced for a while.

I also cleaned up the code in Rift Blade slightly. Its special functions
worked during testing but blocking did not. I'm not sure why at the
moment.