[FIX] GitLab OAuth does not work when GitLab’s URL ends with slash

# Conflicts:
#	package-lock.json
#	package.json

[FIX] Close Livechat conversation by visitor not working in version 0.61.0

[FIX] Formal pronouns and some small mistakes in German texts

[FIX] Facebook integration in livechat not working on version 0.61.0

[FIX] Weird rendering of emojis at sidebar when `last message` is activated

[NEW] Option to proxy files and avatars through the server

[BREAK] Remove Graphics/Image Magick support

[NEW] Allow request avatar placeholders as PNG or JPG instead of SVG

 [NEW] Image preview as 32x32 base64 jpeg

# Conflicts:
#	server/startup/avatar.js

# Conflicts:
#	package-lock.json
#	package.json

[FIX] Rest API helpers only applying to v1

[FIX] Desktop notification not showing when avatar came from external storage service

[FIX] Missing link Site URLs in enrollment e-mails

[FIX] Missing string 'Username_already_exist' on the accountProfile page

[NEW] New REST API to mark channel as read

[NEW] Add route to get user shield/badge

[FIX] SVG avatars are not been displayed correctly when load in non HTML containers