[reSIProcate] dum.addTransport not thread safe

[Hong Yu]

DialogUsageManager::addTransport calls SipStack::addTransport directly.
If DUM and SipStack run in two separate threads, there is possibility
that SipStack starts selecting on newly added transport before the
transport is ready (i.e. before bind returns). 

What's the best way to have addTransport executed within SipStack's
thread? I'm thinking about posting an ApplicationMessage to SipStack's
Fifo queue. But I haven't been able to figure out how to use
ApplicationMessage yet. Any insight on this is appreciated.


Hong