* Implement a skip list for storing rooms
This data structure stores rooms in a given sorted order and allows for
very fast insertions and deletions.
* Export function to get last timestamp of room
* Write tests for the skip list
* Implement enough of the new store to get a list of rooms
* Make it possible to swap sorting algorithm
* Fix comment
* Don't attach to window object
We don't want the store to be created if the labs flag is off
* Remove the store class
Probably best to include this PR with the minimal vm implmentation
fe353542cb