Correct some module func return values, info values, and clear on unload

This makes several changes:
 * Returns correct values / error codes in sceKernelModuleStart() and sceKernelLoadModule().
 * Calculates bss/text/data size correctly as far as I can tell from a few different modules.
 * Cleans up modules on unload by writing out breaks for their text section and -1 for their data (as the PSP seems to; but maybe there are flags?)
 * Returns NOT_YET_LINKED on unresolved function imports, rather than leaving v0 as it was before.

Notably, text size may not be a multiple of 4, which results in a partially-overwritten break instruction.  I've tried to replicate the behavior exactly.

-[Unknown]