Extract permissions functions

[sampaiodiego]

This is the very first step in moving the code base away from any Meteor dependency.

The idea is to do this in parts, without breaking any code that depends on the "extracted" functions. So all extracted functions will be changed to return Promises, but to not break the current code we'll be also exporting those functions with Promise.await, so they'll still run "sync" in a Fiber environment.

So as you can see, here is the new promisified version of canAccessRoom and here is the Promise.await version being exported. So from now on, all code running within a Fiber that wants to use the canAccessRoom function will have to import the Promise.await version (as you can see here)

The same applies to all other rewrited functions like hasPermission.

In order to accomplish that, we had to move away from Meteor collections as well, because they are designed to run within a Fiber. So I have created a new raw.js file in /model directory, that exports the new "raw" (actually, MongoDB driver collections) version of a regular model. The collections methods are being rewritten as needed.

The last bit included in this PR is related to Settings, the same reason as the collections, the old settings objects relies on Fibers, so I've created a simple cached get/set functions feeded by a new observer

users broken