#190. Modifiy remaining extraHeaders reference
Improve 'hostname' parsing (fix #196).
Hold/Mute implementation
Add the sdp task to the default Grunt task
Use grunt-browserify instead of browserify
Update to sdp-transform 0.5.0 (fix #185 and fix #186).
Require sdp-transform 0.5.1 (may fix #46).
Require "sdp-transform": "~0.5.3" (fix missing fields in ICE candidate)
Add Content-Length:0 in ACK for [3456]XX responses (prevent issues with some SIP WS server implementations expecting Content-Length)
Hold/Mute implementation
Add the sdp task to the default Grunt task
Use grunt-browserify instead of browserify
Merge branch 'hold' of github.com:versatica/JsSIP into hold