Get sceKernelStopModule() sorta working

I'm having trouble testing this, I get crashes and I haven't figured out how to actually get output from the module to work well (even writing to ms0 only creates files.)

But anyway, this seems to work roughly right, and may help God Eater and Metal Gear Solid games especially.  I tested it with the God Eater demo, and played a few missions... everything seemed okay, but I didn't go very far / too many different areas.

Also removes the "root" hack in favor of acting like the sce module manager probably does itself, and deleting the start/stop threads once they finish.  This is probably a big part of what helps the memory usage, I think, since before the start thread's stack was never freed.

-[Unknown]