Rename CondGrid to HierarchicalGrid along with its cell.

Rename this grid to match with how life is proceding now.  Its no longer 
guaranteed that the layout of a table will be as expected.  Thus move towards
a more generic system for managing the system.



git-svn-id: https://groke.mcmaster.ca/svn/grad/colin/branches/TableTool_refactor@8640 57e6efec-57d4-0310-aeb1-a6c144bb1a8b