Strava shows climbing but never descending. This adds Elevation Loss next to Elevation Gain on the segment and activity pages.
Adds elevation loss next to Strava's elevation gain for each segment on the segment and activity pages. Also add +/- prefixes to make the numbers clearer.
Strava reports climbing but never descending for segments, and the figure it puts on the activity page isn't climbing either — it's the segment's high minus low elevation, unsigned.
This also fixes a bug where Strava sometimes incorrectly reports zero elevation gain; if gain shows as zero, this recomputes actual gain from the profile.
Everything here is computed from an elevation stream the page already has loaded; nothing extra is fetched.
Before and after images for Segment and Activity pages
