Improved formatting.
Renamed ruter_time_offset().

Renamed the ruter_time_offset() function to time_offset(), as it is private to the translation unit.
Replaced struct ruter_departure with departure_t.

Replaced the usage of struct ruter_departure with its equivalent typedef departure_t to save horizontal space.
Replaced struct ruter_stop with stop_t.

Replaced struct ruter_stop with its equivalent typedef stop_t to save horizontal space. Added the ruter_stop_mode() function which attempts to guess the vehicle mode of a stop.
Replaced struct ruter_line with line_t.

Replaced the usage of struct ruter_line with the equivalent line_t typedef to save horizontal space. Some minor reformatting.
Added typedefs for enums.

Updated API URI and user agent string.
Added guess_stop().

The function guess_stop() attempts to guess the correct stop based on the results from the server.