Optimize for multiple accounts

[Krinkle]

Right now if 2 testswarm-browserstack entries are scheduled (e.g. by different people on different computers, or by an organization with 2 accounts), they both start the same ones (based on neededBrowsers).

It will go faster with more instances doing that, obviously, but it would be nice if instead other instances would first focus on browser that don't have any online clients yet, at all.

So I'd like to change the loop where the workers are started to have another quick loop before it. In there it will first try to add workers to the queue that are neededBrowsers and have 0 onlineClients.

Or alternatively, testswarm-browserstack could be adapted to allow for multiple accounts (e.g. by storing credentials in a json file) and make it ideal (because even if the other instance checks onlineClients, there is a few seconds of delay between the worker create command and it booting and opening the browser etc. so the other script would still do the same) so that it knows which are already being started etc.

[gnarf]

My little rewrite in progress handles this. It prioritizes the needed browsers with 0 clients, then 1 clients - within each it based on needed runs + needed re-runs - and checks for IE within 5 of others and sorts this first