Converted highways from array to dict, indexed by ID number.

Signed-off-by: Ted Steiner <tsteiner2@gmail.com>
Converted Buildings and Features arrays to associative collections.
Issue #5

Signed-off-by: Ted Steiner <tsteiner2@gmail.com>
Added capability to get lists of highways by use, and classify them for plotting and routing.
Concludes issue #7.

Signed-off-by: Ted Steiner <tsteiner@mit.edu>
Can now plot highways according to classification for cars, cycling, and pedestrians.
Use style dictionaries (called layers) to define map styles.
Concludes issue #8.
Related to issue #6 (highways only).

Signed-off-by: Ted Steiner <tsteiner@mit.edu>
Added some robustness checks to handle poorly formatted/unclean OSM files.
Added function to handle getting all data from osm file, so all variables can be locals.

Signed-off-by: Ted Steiner <tsteiner2@gmail.com>
Can now plot large streetmaps.
Reworked data cleaning during crop. Not perfect yet, but works well.

Issue #8.

Signed-off-by: Ted Steiner <tsteiner2@gmail.com>
Can now classify buildings and features by type.
Issue #6

Signed-off-by: Ted Steiner <tsteiner2@gmail.com>
Can now plot feature class layers.
Issue #11

Signed-off-by: Ted Steiner <tsteiner2@gmail.com>
Plot style object now includes a specifier for line or scatter plotting.
Sped up feature layer plotting.
Issue #11

Signed-off-by: Ted Steiner <tsteiner2@gmail.com>
Added capability to plot buildings as layers. Issue #10.
Reordered plotting: Now goes buildings first, roads second, features third.

Signed-off-by: Ted Steiner <tsteiner2@gmail.com>