Properly return success in sceKernelWakeupThread().

Fixes #1596, fixes #1796, possibly others.  I can't believe how long
I stared at this code and debugged it without noticing such a simple
thing...
Wrap the sleep/wakeup HLE funcs.
Report unfinished code in sceKernelAllocateTls().
Return the moduleId in sceKernelUnloadModule().

Final Fantasy 4 very clearly requires this.
Merge pull request #1924 from unknownbrackets/scheduling

Fix sceKernelWakeupThread