Fix for #1411 and #1407. Corrected ill-referenced variables

Improving English language translations

Fix for #1411 and #1407. Corrected the malreferenced variables, was not able to verify #1407 as being fixed since there wasn't clear instructions on how to replicate.

Move all builds - including demo server to develop.   Please merge down to master.

Adding initial en.i18n translations.

Fixing spelling errors, correcting grammar and casing.

Add permission checks to bulk rest api methods

Update from develop

Added liminality.xyz post link

Created and pushed by LingoHub.

Channel settings

* develop:

Conflicts:
	client/views/app/message.coffee

Message type api

Conflicts:
	client/views/app/message.coffee

* develop:
  Fixed conflicts
  added Git Flow and HISTORY.md
  Deletes direct message subscription for users conversing with user being deleted.
  Fix Room model's removeByTypeContainingUsername.  usernames field missing trailing 's'
  Remove the added console log
  Combine the first two checks into one to make it more readable
  Update message pinning to show up on the tab list with a few options to allow/disallow it and whether to allow anyone to pin messages
  Moved oembed code to a template helper.

Conflicts:
	client/views/app/message.coffee

* master:
  Fixed conflicts
  added Git Flow and HISTORY.md
  Remove the added console log
  Combine the first two checks into one to make it more readable
  Update message pinning to show up on the tab list with a few options to allow/disallow it and whether to allow anyone to pin messages
  Moved oembed code to a template helper.

* 'master' of github.com:RocketChat/Rocket.Chat:
  added Git Flow and HISTORY.md

* mitar-move-oembed-to-helper:
  Fixed conflicts
  Moved oembed code to a template helper.

Merge branch 'move-oembed-to-helper' of https://github.com/mitar/Rocket.Chat into mitar-move-oembed-to-helper

# By Mitar
# Via Mitar
* 'move-oembed-to-helper' of https://github.com/mitar/Rocket.Chat:
  Moved oembed code to a template helper.

# Conflicts:
#	client/views/app/message.coffee

Remove direct message subscription for both users when one is deleted

* message-type-api:
  Created RocketChat.MessageTypes class to hold message type rendering rules
  Removed unused 'nu' message type
  Send e-mail on first username set
  Add enrollment email

Add Pinning Functionality

Fixes #1149 where "other" user's subscription for non-deleted, direct message, was not deleted.  This led to duplicate key error if a new user, with the same username as the deleted user, is created and tries to direct message the "other" user.