Improve tests for collapsed geometries.
Fix inconsistent ring detection. Fixes #36.

Two rings should be considered identical when the only thing different is that
they don't start and and end on the same vertex. To detect whether two rings are
the same, we now rotate rings to an arbitrary but consistent starting point.
Fix crash in topojson.mesh with unknown types.
Bump version.
Remove topology argument from topojson.neighbors.

The topology isn't needed to compute adjacency, since that can be computed from
the arc indexes alone.
Bah, fix another bug.
Use round rather than floor. Fixes #35.
Merge branch 'round'