This corrects the handling of lines that are long enough to have two
visible or invisible endpoints, but still cross the small circle and
thus have an invisible or visible intermediate segment.

Fixes #1127.

This allows all listeners with a particular name to be removed.

Fixes #880.

You can now pass a format specifier to scale.tickFormat (for linear, pow and
identity scales). If the format specifier doesn't have a defined precision, the
precision will be set automatically by the scale, returning the appropriate
format. This provides a convenient, declarative way of specifying a format whose
precision will be automatically set by the scale.

This works with axes, too! For example, `axis.ticks(10, "%")` will now use a
percentage format rather than the default format, while still computing the
appropriate precision.

This commit also includes a fix to make d3.format more robust when unreasonable
precisions are specified. Rather than throwing an error, the nearest reasonable
value is used instead.

Fixes #912.

Fix for running `make clean && make -j all`.

This can fail due to a missing d3.js file, which is required for
`node src/package.js` and `node src/component.js`.

Fixes #1134.