Revert "Create group to hold all tickets in a milestone.  Refs #8947."
Revert "Create group to hold all tickets in a milestone.  Refs #8947."

This reverts commit 5bb6d3fa5828afacb1a7378e8399eaa0d1576470.

git-svn-id: 2159781fc7c14c6bdd1f7e265daf7a25099c31e7@11863 7322e99d-02ea-0310-aa39-e9a107903beb

trac-hacks/trac-jsGantt,trac-hacks/trac-jsGantt,trac-hacks/trac-jsGantt