Add setting to disable displaying role tags

Set autocomplete off in form tag
http://stackoverflow.com/questions/12374442/chrome-browser-ignoring-autocomplete-off

Make newly created user join default channels

Improvements to create user via admin.
 Option to send welcome email with login details and password
 Buttons to generate random password
 Make password change on login default to YES

Change enrollment to welcome
Enable checkboxes after save or cancel

Set e-mail verified/not verified

* timeout to close desktop notification after 5 seconds

* added option to set duration in seconds for desktop notifications. implemented setTimeout to close notification after that duration.

* removed accidentally added trailing space

* modified desktop notification settings to accept 0 as value meaning do not set a timeout

* Change naming for opt-out statistics

* Opt out description

* Remove double negatives:

New room notification;
New message notification;
Statistics opt out

* Statistics reporting

* Remove double negative on Disable Favorite Rooms

* Change logic for checking if message and room notifications are enabled

Should cover following issue:
https://github.com/RocketChat/Rocket.Chat/issues/2000