Add a test for sceKernelCreateCallback().
Add tests for refer and delete of callbacks.
Aha, deleting a thread deletes its callbacks.
Oops, cleanup a missing debug check.
Add some tests for sceKernelNotifyCallback().
Test callback order and creation limits.
Add tests for cancel/check/getcount on callbacks.
Merge pull request #102 from unknownbrackets/callbacks

Improved callback tests