Merge as much as possible from Chat-Locker back to our master branch

[engelgabriel]

https://github.com/sscpac/chat-locker

Want to back this issue? Post a bounty on it! We accept bounties via Bountysource.

[engelgabriel]

Maybe @rwakida could start with the permissions features?

[rwakida]

@engelgabriel . chat-locker's permissions are very domain specific. I think most of RocketChat's end users would need something more generic like the roles / permissions task you just assigned me #292. I can tackle this after the roles/permissions task. As you suggested earlier, I'll move this to it's own package.