FS-6707 #resolve #comment add the param iceServers to verto constructor.  possible values: true: enables previous behaviour, false: nowthe default, use no iceServers, ARRAY of iceServer objects: this object will be passed into the browser as-is

Debian has packaged libpq version 9.4beta2.  We were parsing the minor
version as "4beta2" and then trying to treat it as a constant integer,
which obviously doesn't work.

There's not really a perfect way to handle versions like this, so
we'll just pretend it's 9.4.0.

add switch_socket_waitlist for waiting on multiple sockets and abstract it to poll and select so windows can use it too

FS-6686 #resolve #comment increased the timeout to 30 to accomidate situations where the engine takes longer to pick an IP

FS-6682: fix arg order on switch_channel_export_variable called from switch_channel_export_variable_printf #resolve

use final_delivery variable in chat plan to indicate that you do not want to deliver the message to its intended recipient because you have already pre-empted the message