Fixed drag-to-scroll bug
Better control of popups
Merge remote-tracking branch 'origin/0.8.x'
Fixed race in stylesheet load.
Enable quant overlay for POINTS.
Quant-leap improvements.
Nicer sequence-position labels.
Better quantleap.
Properly handle multiple tiers backed by the same datasource when removing tiers
No longer fails on second attempt to get seq length.
Somewhat better chrN vs N canonicalization.
Merge branch '0.8.x'

Conflicts:
	js/browser-ui.js
POINT glyph improvements.
URL salting also done on desktop Safari.
Merge branch '0.8.x'
...
Threshold-leap improvements.
Started moving source adapters out to their own place.
Fixed stripy backgrounds for seq tracks
factored out stylesheet fetchers/default.