Proper 'addr_spec' rule handling
Enhance JsSIP.Exceptions experience

-- Retrieve related useful information for each exception type
Give some love to "console.log|warn|info" messages missing the JsSIP class/module prefix.
Fix 'maddr' and 'method' URI parameters handling
Allow using a JsSIP.URI instance everywhere specting a destination.

Do not limit the target to be only a String.

Ie:
- ua.call(target,..)
- ua.sendMessage(target,..)
Fix stun_host grammar rule.
instrunctions to fetch'n'merge from cloned repo
 * SIP DTMF via INFO / grant media access once

 Implementing DTMF signalling via SIP INFO packets,
 this works if you're calling through a third party
 (eg a pbx) that will translate your signal into
 a proper RTP Payload for DTMF Digits (RFC 2833).

 Grant access to media once per session. This way
 user hasn't to give permission for every call.
 We set a fake session in the beginning and use
 the stream object for all other session we will use
 for future calls.
avoid to emit twice js event on SIP MESSAGE
mediaTypes (now is plural)
 adapt our trick to grant media access only once
FIX: fixed an error raised on parsing IPV4 adresses because of wrong output data type
keep your message updated
fix conflicts due to rebase fixing conflicts :)