You can clone with
HTTPS or Subversion.
I just saw that in Piwik 1.9.1,
If I create a new goal tracking if the page title contains "civicrm/contribute/transact?reset=1&id=30" and then I edit it, it transforms to "civicrm/contribute/transact?reset=1&id=30", so if I change another thing (say, the goal default revenue) and then save without checking the tracked URL, that goal does not work no more.
Thanks for the report. A related report: #3146
Fixed in git master (probably due to switch to Twig template engine)