dart-lang/pub_semver — pull request #2 by ussuri (2014-10-24 21:51:52+00:00)
Title: Support ^1.2.3 and ~1.2.3 as per Bower flavor of semver

Also add:

* Some provisional support for `*` and `x` in version parts, as in `1.2.x`.
* Support for optional leading `v` or `=` in versions, as in `v1.2.3` or `=1.2.3`.