Patch for migration of hours balance from accounts to members.

All of the following changes were made to support the migration of
hours balances from accounts to members. Changes in include the
following:
 - Changing of all MESS user templates that reference account hours
   balance
 - Creation of reports that show member hours balances
 - Python script that migrates account hours to member hours
 - Creation of Member Hours Balance form in reports
 - etc.
Re-added "Over Balance" report which was removed from Accounts report
list by mistake.