Optimize for reduced boundary file size and faster loads

[karimbahgat]

• Use quantization to reduce file size.
• Maybe gzip each topojson which should result in substantial reduction (but not sure if can be read by openlayers).
• Maybe create a separate simplified topojson for simple display purposes (altern look into maptiler)...
• Switching to geobuf wrapper around topojson should result in much more substantial speedups.