Retrieve Tags For A Commit

[mattfarina]

The idea is to retrieve a list of tags associated with a commit.

In Git you can use git describe --tags --exact-match <COMMIT ID>

In Bzr you can use bzr tags -r <COMMIT ID>

In Hg you can use hg log -r <COMMIT ID> --style=xml. A tag will be present if one is associated with the commit.

In SVN we aren't supporting tags since they are part of the path.

[mattfarina]

This was implemented by #27