Add back check for "is busy" in bnode_Delete

This was dropped in "bozo: pthread locking for bnodes list" without
mention.

Change-Id: Icd8f0fbe75c8c0f3b60b53e037d0f6ea4631183b
Remove @@@ comment in bnode_NewProc

I audited all the callers, we should already have a ref here.
Document this invariant with an assertion, and also add a comment
near BOP_PROCEXIT noting why there is a bnode_Release call (which is
related to why we know we already have a ref on the bnode).

Change-Id: I58b2848d877d0518efe7c81cc4ec3a5bb4046c9f
Update bnode_Write comment

The locking strategy is not exactly how I described it.

Change-Id: I7064a3153e37c4f7c26026a7124a5e71038e5c6d
tbozo: don't create install-tree directories

tbozo depends on bozo, and bozo creates these directories already.
There's no need to have this as part of the install/dest rules.
(See, e.g., tptserver.)

Change-Id: I4f784368f43f8ccf4954d95f6575d165dbdf74a9
Lock the bproc_mutex before sleeping on it

Otherwise, undefined behavior results.

Change-Id: Ie13504de2f65ec0e0e5e7bc94ba4899d977fc5b1
Return NULL from bnode_SoftInt, not 0

The signature claims we return a pointer, so, well, do so.

Change-Id: I4adce32b75b77d88b9a34154b750535faa6a6fc0
In proc_handler, use 'tp' instead of 'tproc'

To be consistent with our caller.

Change-Id: I79d8e49d7e9ca59c346c5857fa96f23e7332923b