OpenTreeMap/OTM2 — pull request #1284 by RickMohr (2014-04-08 17:33:50+00:00)
Title: Distinguish between next/prev marker and next/prev point

* When getting next/prev marker, look in `_markers`
* When getting next/prev point, look in `latlngs()`

With other recent fixes (mistakenly committed with #1283), fixes #1258, fixes #1260