Tabbar rework

Created and pushed by LingoHub.

Merge branch 'feature/app-language-setting' of https://github.com/sweetvvck/Rocket.Chat into sweetvvck-feature/app-language-setting

Merge branch 'allow-disable-form-login' of https://github.com/LearnersGuild/Rocket.Chat into LearnersGuild-allow-disable-form-login

No need to reload server for SMTP settings to take effect;
Closes #1246
Checks SMTP Settings in #1492

Update README.md

fix typo on docker tag

# By Diego Sampaio (8) and Rodrigo Nascimento (2)
# Via Gabriel Engel (3) and Rodrigo Nascimento (2)
* 'develop' of github.com:RocketChat/Rocket.Chat:
  Increase the delay to render color fields
  fix guest users default role
  standardize colors definition
  improved clean button color
  support named color for message attachments
  added request debug messages
  trim integration messages
  Try to parse all request bodies as JSON
  new password reset screen
  fix reset password - closes #1502

Intregation improvements - fixes #1759