Updates PlanningBox properties : it is now possible to update directly

all PlanningBox Properties through the /manage interface
Updates Report group processing to handle multi acivities per group
Implements support for multilines display in case several actiities are
rendered per group
Corrects block text display : do not use Group properties but acivity
properties instead
Updates Validator to handle modifications over multitasking


git-svn-id: https://svn.erp5.org/repos/public/erp5/trunk@7058 20353a03-c40f-0410-a6d1-a30d3c3de9de