This commit introduce a full redesign of all JS views.  We started
basically from scratch.  The goal was to unify all the various views
under a common framework, to make them testable, to make then usable in
different conditions (in studio, or in the frontend), and to make our
lives easier.

Some important points are:
- we introduced new coding guidelines (camelCase, 80 chars width, ...)
- we have a brand new testing framework (still QUnit based)
- kanban view moved to the web addon
- calendar view (formerly web_calender) moved to web as well
- the tree view was removed
- all new code should be documented

We hope that this code is the start of a new era for the Odoo web
client, we want to have a high quality codebase, well documented, well
tested, well designed.

Work done by the framework team: mostly aab, ged, chm, dmo, qsm

Also:
 - keeps unticked filters unticked when deleting a filter or adding a new one
 - correctly tick filters when clicking on the partner's name (that code was
   broken)
 - remove reference to instance.web introduced by a forwardport
 - wrong use of self in CalendarView's init()

Before this rev., the events were loaded twice:
 - once with the date range as domain (and optionally the content of the search
   view),
 - once with the date range and the partner_ids of the sidebar's filters (and
   content of search view).

The first loading was therefore useless, and might also be very costly.

Load the fields_view of all views of the action together. If a searchview is
required, also load its fields_view and its filters.

Use lazy-loading for fields as they are required for the Pivot and Graph
views only, and may be used by Filters and GroupBy menus of the Search view
if the users clicks on 'Add a custom Filter/Group'.

The fields are thus also loaded directly if the first view of the action is
Pivot or Graph, and otherwise, they are lazy-loaded when/if the user opens
a Pivot or Graph view, or if he wants to add a custom Filter/Group.

Some refactoring of views API as well:
- Views must now be instantiated with their fields_view
- Move code requiring fields_view from start() to init(), or willStart() for
  heavy processing.
- Remove view_type attribute from views as it was used to call
  fields_view_get.
- Remove view_id parameter to views' init as it is no longer used.
- Move duplicate code from various views' init to the View widget.
- Remove view_loading() function from views as they now follow the classical
  lifecycle of widgets (init -> willStart -> start -> destroy).
- Searchview now extends View like all other views.
- Remove useless function guard_active() as it was used for the form_view's
  action buttons to wrap handlers to ensure that they are executed only if
  the form_view is the current active view. This is not useful anymore as
  from v9, views and their control panel are appended in the DOM
  simultaneously, so one can't click on a button of a view which is not the
  current active view.

In 22051dc, the sidebar contacts of the calendar were ordered, this does
it in another way to solve several issues when selecting filters.

The title of the parent is located in the "title" field.

opw-666577

as the quick create is also used to create e.g. leads, not only events.

- Contact filters were dropped with the new design
- The 'me' filter was not working correctly (wrong colors)
- Remove some useless/unnecessary code
- Use new API confirm dialogs
- Convert CSS to LESS