* Remove previous hack to round value.

  * Use generic script Base_getPreferredPrecision and Base_getRoundValue to get the right amount of money.
  * Clean up code (supress old-school 80-character limitation, regroup similar statement together for easy human-eye parsing).
  * Use section_portal_type_list to break acquisition of 'group' property from Person to Organisaiton.
  * Show the the right date on the previous balance line.

git-svn-id: https://svn.erp5.org/repos/public/erp5/trunk@6367 20353a03-c40f-0410-a6d1-a30d3c3de9de