Add proper menu and groups for company

I think the company module should be put outside the party entrypoint and have its own groups for access rights (company & employee).

assigned to @ced

added company type::feature + 1 deleted label

added 1 deleted label and removed 1 deleted label

review286291002 updated at https://codereview.tryton.org/286291002/#ps282411002

New changeset 585f9ae60bd7 by Cédric Krier in branch 'default':
Add company top level menu entry, company and employee groups
https://hg.tryton.org/modules/company/rev/585f9ae60bd7

added 1 deleted label and removed 1 deleted label

closed

New changeset 655b943cae8f by Cédric Krier in branch 'default':
Add company top level menu entry, company and employee groups
https://hg.tryton.org/modules/timesheet_cost/rev/655b943cae8f

New changeset 43c19f808bb5 by Cédric Krier in branch 'default':
Add company top level menu entry, company and employee groups
https://hg.tryton.org/tryton-env/rev/43c19f808bb5

New changeset 3b4ab1cd971f by Cédric Krier in branch 'default':
Add company top level menu entry, company and employee groups
https://hg.tryton.org/modules/company/rev/3b4ab1cd971f