Stop practicing thread necromancy.
Disable sceKernelDelayThread() w/intr disabled.

But automatically resume the dispatch thread if only it is disabled.
Oops, disabling a subintr did not work.
Update tests.
Disable common wait funcs while intr disabled.

Per PSP tests.
sceKernelDelaySysClockThread() cleanup.

It doesn't wait either of course.
Return proper errors while dispatch disabled.

In at least the majority of waits.
Disable some common waits inside interrupts.
Merge pull request #3452 from unknownbrackets/scheduling

Improve some scheduling issues, deny many waits inside interrupts