v0.5.0

• Update sorts for pois and places
• Update kind calculation for roads to include aerialways
• Add volume calculation transform
• Update road sort key calculation
• Remove scalerank for neighbourhoods
• Allow exterior boundaries to be snapped to a grid
• Improve exterior boundaries processing
• Add post processing functions:
  • generate address points from buildings
  • drop certain features
  • drop certain feature properties
  • remove features with zero area
  • remove duplicate features
  • normalize duplicate stations
  • only keep the first N features matching a criteria
  • rank features based on a key
  • normalize aerialways
  • numeric min filter
  • copy features across layers
  • replace geometry with a representative point