[IMP] crm: stage management

Stages are now sales team dependant, and not shared anymore. This comes
with a sales-team way of working :
- sales team is the entrance point, click on the big Pipeline button to
see the opportunities pipeline of this specific sales team
- no more opportunities menu entry, as you should come from a sales team
- leads are still sales-team agnostic

The stage management has been updated :
- Won is still a stage (probability=100, onchange=1).
- Lost is not a stage anymore. Lost is equivalent to archiving. Archiving
uses the active field. Setting a lead or an opportunity as lost set them
as unactive.

Downside of the no more share policy: multi sales team opportunities
management can quickly become complicated. Indeed you may have stages
with the same name, not being the same stage, therefore not displayed
in the same column. Grouping on the stage name leads to other issues
(sequencing incoherence, impossible to drag n drop), so this is not
an option.