Osmnx

- remove deprecated buildings module
- filter steps ways out of bike queries
- convert CRS-handling to proj4 strings
- save graph to xml-formatted .osm file
- minor refactoring

- deprecate buildings module and replace with generalized footprints module
- improve handling of multipolygon footprints
- new function to find nearest edge(s), given coordinates
- add "search," "reverse," and "lookup" nominatim queries
- use unprojected graphs for figure-ground plotting functions
- allow non-integer osmid values for custom data
- improve get_route_edge_attributes function
- improve color mapping by node/edge attribute value
- make bidirectional network types explicit
- networkx compatibility fixes to resolve warnings

- add python 3.7 compatibility
- add convenience function to plot several routes over the same map
- optimize graph truncation to bounding box
- give self-loops a null bearing when calculating edge bearings
- make accept-language http header explicit and configurable
- add citation function
- refactor POI module

- add Gephi compatibility argument for saving GraphML
- handle square bracket encapsulated strings when loading GraphML

- add ability to retrieve points of interest
- improve performance for retrieving huge geographies' street networks
- fix building footprint retrieval query syntax
- minor bug fixes

- add fast nearest-nodes search
- allow custom network query filters
- allow create_graph to return graph with no edges
- improve figure_ground joint smoothing
- fix handling of parallel edges when making multidigraph undirected
- generalize same-geometry checker
- improve detection of prior topology simplification
- custom error types for finer-grained handling