remove import for missing shapefile
Merge pull request #60 from mapzen/remove-import-missing-shapefile

remove import for missing shapefile
query optimizations

* create indexes for columns used in queries
* always use pre-computed way_area
  - add way_area column to tables lacking it
* create additional columns to store pre-computed values
* remove redundant vtm queries
* add columns to store simplified geometries
suppress_simplification config where appropriate