minor fixes.
Add Layers control and multiple layers to maps.
Fixed location of leaflet images.
Exclude bikeways removed in 2014 from statistics and JSON (they appear to be replaced in 2014)
Add clearonly=1 argument to generate_json - addresses long running request issue.
Fix cache key bug when generating new JSON.
Add bcc information and improve formatting of wayinfo.html
Update copyright/attributions.
Improve streetview url generation, anticipating future changes.