Wrap sceKernelGetThreadExitStatus().

So it's usable internally too.
Use a custom RA for module funcs.  Not used yet.

But it will be.
Get rid of the "root" return hack.
Add a wait type for modules to handle return right.
Initial implementation of sceKernelStopModule().

Not perfect but should be functional.
Remove comment.
Merge pull request #1935 from unknownbrackets/modules

Get sceKernelStopModule() sorta working