Unalias Model field names

- Assume that all JSON from the KnowTime server has field names matching
  the names listed in the GTFS reference:
  http://developers.google.com/transit/gtfs/reference

- Rename getters to match (except in camelCase) the names listed in the
  above reference.

- Add toString() for each model.
Update version number
Merge branch 'feature/remove_aliases' into develop