Purpose is to replace existing inherits of resource.resource by an inherit
on the mixin itself. The mixin offers several methods to compute working
intervals, attendance, hours, ... This mixin will be improved in future
commits when new methods that will be required with future improvements
of various service apps.
This commit also adds tests for the mixin itself. A new model is defined
only for testing purpose to test the mixin.
Purpose of this commit is to always have a default calendar for each
company and ensure it is correctly set on resources.
Some cleaning is also performed in resource models to remove unused
fields, improve labels and make views a bit more odoo-ish.
* [REF] res_company: add a m2o to the default calendar to use in the
company as well as a o2m linking all resource calendars used in the
company. Some code has been added to correctly update existing
companies when installing the module;
* [REF] resource_calendar
* [REM] manager field on resource.calendar: this field is never used
and is not necessary anyway
* [ADD] global_leave_ids: filter leaves on a calendar to see global
company leaves
* [IMP] better default company / calendar computation to ensure there
is always a calendar attached to a resource
* [IMP] improve resource and calendar views in order to look more like
other odoo views