cleanup process spawning, remove mutex lock and add session to listener only if reply state and session flag is set to waiting FS-3432

At least until we can distinguish the meaningful ones from the noise.

When a call is being setup, a couple seconds of audio may be sent
unencrypted.  This seems to trigger the log message here with every
such packet.

This amends commit 7bd9efc7.

We changed away from using unsigned here because it caused a warning
on Windows.  Using the more specific type, however, is causing a
warning on gcc-4.7 (it notices that the switch statement contains
values not present in the specified enum type).  So we're switching
back to unsigned here while keeping the type casts and hoping that
keeps Windows happy.

Update the outgoing channel handler so it passes the "var_event" event down towards rtmp_send_incoming_call since variables passed using originate are not yet in the session before the outgoing channel function returns.

block any inbound messages when queue is full; add debounce for mwi and pres on register; fix missing detach attr on new mode to process reg in new thread

 FS-4224 --resolve this was a regression from d6374535 to fix FS-3029, when you find a profile you must release it

This amends commit 7bd9efc7.

Using the more explicit typedef causes gcc to warn about the
incompatible types for the reasons noted in the earlier commit
message.  This is why we just used the unsigned type earlier so we
could avoid all this casting.

The things we do to make Windows happy...

According Jeff Lenk, Windows Visual Studio doesn't understand that
people use the char type for non-null-terminated byte arrays, so it
throws a warning about this that causes the build to fail on Windows.

As the initial value for the ZID doesn't really matter here one iota,
just null-terminate it on Windows.