Added 'registrar_server' UA configuration parameter. See the doc at http://jssip.net/documentation/devel/api/ua_configuration_parameters/#parameter_registrar_server.
Rename causes.IN_DIALOG_408_OR_481 to causes.DIALOG_ERROR and add causes.RTP_TIMEOUT.
JsSIP uses JSLint rather than JSHint.
Add http:// to URL in Grunt banner field.
Merge remote-tracking branch 'upstream/master'