Add d3.geo.project(object, projection).

Given a GeoJSON object (such as a FeatureCollection), returns a new object of
the same type with the coordinates projected using the specified projection. The
projection is applied by using a buffering output context, and thus incorporates
adaptive resampling and clipping, if any.
Use symbols rather than properties.
More concise.
Insert closing point for polygon rings.

D3 doesn't emit a closing point for polygon rings, so this needs to be
reinserted since it is required by GeoJSON.

If there are fewer than 3 points emitted, then we reinsert the first
point more than once, which TopoJSON also does.  Alternatively, we might
consider generating a line or a point in this situation.
Add simple test for d3.geo.project.

Also, remove the dependency on all for the test target.
Simplify test rule.
Bump version.