`external_pending' => `unknown_pending'
`set_length' => `drop'
`set_synchronized' => `update_unknown_pending'
revert `set_synchronized' => `update_unknown_pending'

Matthias likes the old names better, arguing that the main purpose of that
function is to do that mnesia transaction.
style
cosmetic
refactoring: inline helper function
refactoring: make the var match the field
Test that simple_one_for_one_terminate shutdowns no longer deadlock and
handle reporting errors not caught during shutdown (e.g., 'killed' pids)
store the depth of master and slave instead of the unknown pending msgs
forgot debug line in
attempt to close ssl connections gracefully but forcefully
gracefully...so that there is a good chance of TLS alerts making it
through, but forecfully (after a timeout) so we don't get stuck (or
worse, silently) holding on to file descriptors and processes.
Introduce additional, non-smp tests (using suspend) and explode the test
fixture list to create 400 repetitions of the group
cosmetic
construct child exit reason in the right place
reset and join when changing node type
cosmetic
oops
cosmetics
remove useless test case