Create and push git-style tags

Created originally on Bitbucket by jaraco (Jason R. Coombs)

I'd like for hg-git to supply a new command, something like git-tag, that adds a tag to the .hg/git-tags and then includes those tags when pushing to a git repository.

The issue with using simple Mercurial-style tags is that they're maintained in the Mercurial history, including references to Mercurial hashes which will only exist on that individual's checkout. Furthermore, hg-git won't pull the relevant git tags if there exists Mercurial tags by the same name, so hg-git checkouts of the git repository won't be able to see tags added in other hg-git checkouts until the .hgtags file is flushed.

Is there any reason to think that hg-git couldn't support creating git-style tags?