Created an instructions dialog, on large devices.

Alerts the user that they need to drag the centerpoint around the map to choose
the spot. Is intended to work around a common problem where users misplace
points because they don't understand the point will be placed at the centerpoint
(or they don't even see it!)
no more free sandboxes on dotcloud...
cleaned up the intro.
clarified backend options.
Merge pull request #10 from CrowdSpot/instructions

Created an instructions dialog, on large devices.
Comment out ped_obstacles flavor in the local_settings template
Fix reference to layer type
add rainbow of triangle markers
Merge remote-tracking branch 'upstream'

Conflicts:
	src/sa_web/static/css/style.css