Add nighttime theme
Update data sql (merge from master)
Update previews
Merge remote-tracking branch 'origin/master' into develop

Conflicts:
	brick-labels.xml
	brick-labels_halo.xml
	brick-landcover.xml
	brick-roads.xml
	brick.cfg.py
	mapbox/labels.mss
	mapbox/landmass.mss
	mapbox/project.mml
	mapbox/roads.mss
	mapbox/style.mss
	sample-0.jpg
	sample-1.jpg
	sample-2.jpg
	sample-3.jpg
	sample-4.jpg
	sample-5.jpg
Merge branch 'release/1.4'