#2 Fix for infoElement

[Warren Milward]

Change to infoElemet:

Note also that I can't compile it without removing the const keyword with MSVC.

template <class _InfoElement>
_InfoElement& infoElement() const
{
typename _InfoElementsMap::iterator it = infoElements_.find(_InfoElement::infoElementID);
if (infoElements_.end() == it)
throw typename Base::failure("TPUserData: Information Element not found");
// WMM - start
// return *it;
return dynamic_cast<_InfoElement&>(*it->second);
// WMM - end
}