Strava Heatmap to OSM Background

What does this extension do?

Strava allows using their global heatmap for tracing on OpenStreetMap. However, following a recent update the publicly offered heatmap resolution was greatly reduced making tracing impossible. The high resolution heatmap is still available for logged in Strava users and this is where this extension comes in: it constructs a URL with the high resolution heatmap ready to use in jOSM and other OSM tracing tools.