[#53173673] chat prototype (not finished)
[#53173673] chat prototype (fixes)
[#53298585] Передаем app_key для api в заголовках
Merge branch 'dapi/chore/app_key_in_header' into develop

Conflicts:
	assets/javascripts/controllers/informer.js.coffee
	assets/javascripts/v1.js.coffee