Having made more than 4,000 per cent since 2001, ICON’s shareholders haven’t had much to complain about.  The one thing that has stuck in their craw is ICON’s debt – or lack of it. The company has more cash than it has debt. Most companies fund themselves partially with borrowed money which, in turn, increases returns for shareholders. ICON’s M.O. has been to grow steadily through small acquisitions, funded out of cash flow. “They’ve always done tiny bolt-on acquisitions,” says Donald Hooker, an analyst at Key Capital. “Shareholders sometimes got frustrated because the acquisitions were never enough to move the needle.”…