Thread ID management by capmgr

[phanikishoreg]

In the current system, we use cos_introspect to get the THDID from the kernel for any given thdcap. Going forward, capmgr will be managing creation and deletion of capabilities, it should be easy to change the system so that we provide the thread id for each thread from the capmgr, rather than having the kernel contain that policy. (used comment from @gparmer on my PR#315)

[gparmer]

Rephrasing this: We should remove the thread id and naming logic from the kernel.