HTML5 Speedtest - Multiple Points of Test

Work in progress!

This branch isn't stable yet, don't use it in production.
Documentation isn't done yet.

Multiple Points of Test

This branch allows usage of multiple test servers instead of just 1. The client runs a server selector, which pings a list of test servers and chooses the one with the best ping.

Frontend server

This is the server that hosts the UI, the JS files, and optionally the telemetry

Test backends

These are the servers to which the clients can connect and actually do the test. They don't host the UI, only the PHP files required for the test.