Support more OSM tags for selecting stops

[ialokim]

As pointed out here and here, the current code of the OsmConnector class is very specific to buses. We should change that after merging in #99.

[xamanu]

The comments you linked mostly refer to including nodes with public_transport=stop_position as potential stop candidate, instead of only selecting public_transport=platform; same for its role in the route relation. As a constraint we have to male sure that either one or another is taken. Not both.

And there is also highway=bus_stop widely used and we might want to support it.

I guess we'd have to implement a new setting in the config file:

• stop_type=platform (default if omitted)
• stop_type=stop_position

[stronk7]

Not the same, but somehow related... I've found that, while fetching information from OSM, both platform_entry_only and platform_exit_only (PT2 good practice, if I'm not wrong) are completely ignored and only relation elements with role platform are considered.