Sales documents permissions by channels (teams)

This module adds a new "Sale" group called "User: Team Documents Only", that
includes the proper permissions for showing only the information related
to that user sale team (having assigned that team/channel or no team at
all, independently from the assigned salesman):

- Contacts.
- Quotations/Sales Orders (implemented in sales_team_security_sale)
- Leads/Opportunities (implemented in sales_team_security_crm)

It also handles the sync (auto-creation and remove) of followers in
company partners and childs of them according to salesmans. Any example
about it: - Partner company \> Salesman: Admin - Partner company,
Contact 1 \> Without salesman - Partner company, Contact 2 \> Salesman:
Demo All these partners have these followers: Admin + Demo

And finally, there are rules for partners to be restricted to the own
ones for the group "User: Own Documents Only" for being coherent with
the permission scheme. Someone with this permission will see:

- Contacts without salesman assigned.
- Contacts with them as salesman.
- Contacts with them as follower.

For keeping consistent accesses, followers of the main and
shipping/invoice contacts are synced according the salesman of the
children contacts

Additionally, users with the "User: Team Documents Only" group can see contacts
created by any salesman that belongs to the same sales team(s), allowing
team members to view and access contacts managed by their teammates.