https://github.com/gotwarlost/istanbul/compare/v0.1.46...master

The biggest feature here I would like is a comment syntax for explicitly ignoring things for code coverage. The potential for adding a `.istanbul.yml` config file is a nice-to-have, as well.

There are no explicit bug fixes that I'm aware of, but the minor version bump seems like just paranoia on the author's part:
> Up minor version due to the new way in which the global object is accessed. This _should_ be backwards-compatible but has not been tested in the wild.

The success of the tests seems to indicate that the concern was unfounded.