Payloads: add the SPASpec payload
Sidebar: migrate all the signin/signout to the sidebar
Worker: remove all of the signin/signout code from the worker
Sidebar: make the SPA setup persistent
Fix tests
Add payloads to jshint global list for sidebar
Payloads: add JSDoc for each payload
Fix tests
Merge branch 'master' into remove-harcoded-login

Conflicts:
	static/js/spa/server.js
	test/frontend/spa/server_test.js
Toggle help bubble message between Mute and Unmute microphone
Payloads: fix minor typos
SidebarApp: remove obsolete event handlers
SidebarApp: remove a misleading comment
TalkillaSPA: update the connected event contract

Now it respect more closely the documentation
Minor tests improvements
Checking with hasClass method is prefered because it is more resillient to UX changes
Test that the title of the microphone mute button changes
SidebarApp: improve signin/signout-requested events tests

Remove tests from the constructor describe block and move them into independant
event tests.
SidebarApp: test the talkilla.worker-ready event
Merge pull request #302 from tOkeshu/remove-harcoded-login

Migrate the Persona login to the sidebar