Monitors the performance of Rust master. Heavily inspired by arewefastyet.com (including borrowing JS and CSS!). A fairly quick hack: doesn't do anything fancy, just hits the buildbot JSON api and puts it into a database, and then (separately) constructs a JSON file (`perf.js`, which sets the `PERF_DATA` global variable). It also collects data from some benchmarkers to disable detailed memory vs time profiles as well as accurate build speeds. Requires Python 3 and the requests library.