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

Avoid duplicating web addon in enterprise by extracting a common basis.
Enterprise features stay in enterprise, but use that common basis.

Mainly:
 - JS refactoring and linting
 - Conversion of .sass into .less split into multiple files
 - Templates cleaning and DOM simplification
 - Re-generation of web.pot, and update of .po files

Introduction of 'data_manager' service which handles meta-data related to
actions and views (fields_views, fields and filters). Ideally, all RPCs to
get that kind of information should go through data_manager, as it holds an
internal cache.

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.

The module system needs to know the dependencies of a given module
before executing the function.  This is why the dependencies were
defined once in an array, and then were described one more times in the
call to require.

But a trick can simplify this: the boot function can parse the string
representation of the module and extract the calls to require from it.
It is more work for the processor, but it leads to simpler module
definitions.

This commit introduces a new module system for the javascript code.
Instead of using global (namespaced) variables everywhere (like
openerp.web.whatever, ...), each file declare one (or more) module
with its dependencies.  Each module will be loaded after its
dependencies, and will be given a reference to the return values.

This change is a massive departure from the way the client worked
previously.  It will sadly break some/most history, but I am sure that
the future git ecosystem will allow you to easily browse the history
past this revision (one can dream).

This commit feature:
* main namespace is now odoo instead of openerp
* a way to define modules and dependencies (inspired by requirejs)
* many files have been splitted in simpler subfiles
* basic support for debugging in odoo.__DEBUG__
* no global variable (i.e. nothing in window.openerp)
* many bug fixes, many new bugs

Future vision: this modularization should simplify future code
development, simplify debugging and will allow a serious testing effort