Mercurial activity extension

This is mostly a maintenance release, fixing few bugs. Other noticeable stuff includes:

• it's now possible to provide a title
• added lot of 'short-form' options
• some options have changed, check your scripts
• the wiki now has a documentation page describing integration with web interface and unit tests.

As usual, you can clone/update your repository, or download a tarball from the tab 'file', upthere.