Added theme color for FxOS 2.1+

Closes #580
Fixed meta tags for https version
Fixed pestañas

https://twitter.com/andyarias17/status/535129689413918723
Disabled instance manager for packed app
Fixed typing from draft and switch peer
Fixed text field styles
Added simple user blocking
Updated desktop media modals

New photo viewer with preloads
New video modal
New document modal
Fixed add user from shared contact
Fixed contact attach
Added mobile-friendly photo/video viewer

Closes #479
Improved FxOS downloads
Bump to 0.3.6
Fixed soundcloud regex

Closes #574
Added Dutch localization from Transifex
Updated translations
Fixed locales
Added Portuguese (Brasil)
Synchronize translations with Transifex
Upgrade to 20th layer