SIP.js 0.6.2 + patches
Allow '0' as a DTMF tone.
Gruntfile.js: tell uglify to give ascii output

see https://github.com/onsip/SIP.js/issues/106#issuecomment-57349358

resolves #106
UA#onTransportError: don't try next transport if UA is closed

addresses #63
Gruntfile.js: uglify once, copy twice

This trims roughly 1 second from `grunt build`
Gruntfile.js: remove templates from banner string

Simplify browserify's postBundleCB
src/SIP.js: fix indentation
Remove explicit false check for DTMF tones.
Merge pull request #105 from Bat-o-matic/master

Allow '0' as a DTMF tone.
Logger, LoggerFactory: dedupe error/warn/log/debug definitions
Move Logger definition into LoggerFactory.js
LoggerFactory: iterate over `levels` to define error/warn/log/debug
simplify LoggerFactory#print
WebRTC.MediaHandler/MediaStreamManager: support multiple MediaStreams

MediaHandler:
  #addStream -> #addStreams: takes (Array of) MediaStream
  #render: renders only first local/remote stream (see #76)

MediaStreamManager:
  .render:
    * takes (Array of) MediaStream
    * renders only the first (see #76)

  #acquire:
    * returns a Promise of Array of MediaStream
    * mediaHint.stream is (Array of) MediaStream

  #release: takes (Array of) MediaStream
WebRTC: isSupported doesn't require getUserMedia

This allows the default MediaHandler to be used without capturing media.
Merge remote-tracking branch 'upstream/master'