Allow to delete a cancelinvoice in draft mode
Ref #103 : only set task name if not set yet
Ref #103 : add a metadata edition state

Replace the phase change state with a more generic one
Ref #103 : Metadata edition form
Ref #103 : provide a field for task name edition
Ref #103 : Allow metadata edition
Fix #103 : enhance the project view
Fix company invoice list

Fix is_admin_view var
Remove doc description if admin
Fix missing pager in activity list
Add an expense list view
Enhance the main form node builder
Add a menu entry
Add a payment view module
Handle valid cancelinvoices in the topay function

Now we take in consideration the associated cancelinvoice in the topay
method.

invoice.topay now return what is really left topay
Remove the status validation method from the task model
Add a traversal entry for payments
Enhance the payment schema for edition
Add a payment view
Add links to the payment page
Fix tests on invoices