Remove password confirmation when logged in via oauth

Add ability to hide embedded media

Minor filename fix on 'burger' view

When no password is set (logged in via oauth), don't ask for password
when saving profile and ask for username when deleting account.

Not sure if this was annoying anyone else, but I figured I might as
well try to help out where I can.

Review owner moderator permissions

Conflicts:
	packages/rocketchat-lib/i18n/zh-TW.i18n.json
	packages/rocketchat-ui-admin/admin/users/adminUserEdit.coffee
	server/startup/migrations/v37.js

Embedded media like images and video can now individually be collapsed

A new preference "Collapse media by default" is also added, the default
is to not collapse media.

Since images are not always shown, "showImage" is also renamed to
"loadImage"

Closes #1187

Created and pushed by LingoHub.