This is a simple renaming without adaptation.

- Review UI custom colors (used for tags and kanban cards)

- Properly align control panel items

- Remove links style overrides (these rules are not necessary anymore
  because already specified in bootstrap_overridden.less variables
  definitions)

- Set new webclient bg color

- Adapt colors in kanban view

Datapoints of the BasicModel store the data fetched from the
server and changes done (not saved yet) by the user. For x2many
fields, datapoints are of type 'list' and have a 'res_ids' key
containing the ids of all records in the relation. They also have a
'data' key containing datapoints of type 'record', representing the
records in the relation that have been fetched (with a limit set to
40 or 80 depending on the subview used). So basically, the length
of res_ids may be different than the length of data.

Before this rev., the changes in x2manys were saved under the key
'_changes' as a duplication of the content of 'data', i.e. same
list of datapoints of type 'record', modulo the changes done (it
contained the new records added and didn't contained the removed
records, whereas the 'data' remained unchanged). This didn't worked
at all when there were more records than the limit in the relation.
Indeed, when this happened, the commands to send to the server
couldn't be generated correctly.

This rev. modifies the way changes are stored in those datapoints.
Now, each change is stored as an operation. An operation could be
of type 'ADD', 'REMOVE', 'REMOVE_ALL' or 'UPDATE'. As before,
'data' remains unchanged and always keeps the datapoints of records
that have been fetched (the ones that are currently displayed in
the list or kanban subview). This way, commands can now be properly
computed.

This had a nice side-effect of fixing two other bugs linked to
x2manys.
First, when used in a context (e.g. {some_key: some_x2many_field}),
the value of some_x2many_field (i.e. a list of commands) was always
[] if the field was invisible="1" in the view, because it's
subrecords weren't fetched, and the generated commands were based
on them. Now, they are generated from the list of res_ids in the
relation, so it works fine.
Second, the x2many records are supposed to be sorted client-side,
after being read, and after each edition. This was working in the
first case, but not in the second. Now it's working even after
a record edition.

This rev. also correctly sets the 'parentID' and 'static' keys in
datapoints.

Finally, we also fixed the pager in x2manys as it was badly
displayed (small less tweaks).

Since the new views merge, a lot of design elements were broken. This
was particularly impacting the fields in the editable list view; indeed
the editable list view is not using an inline form view anymore so the
fields in the list were not properly styled as the LESS was still
defined assuming the form view environment (for example the invalid
fields were red for o2m fields in form view but not in editable list
view even though they got the right CSS class).

This commit refactor the LESS following these rules:
- No more division of non-layout and layout rules. Dividing LESS rules
  in x_layout.less and x.less was a mistake. Many rules can be
  considered to be layout and not layout at the same time, developers
  always have to switch from one file part to the other, many CSS
  selectors (and rules!) are duplicated for nothing, ...
- Field style is extracted from x_view.less and put in the new
  fields.less file. As before, the fields_extra.less will contain the
  rules specific to community so that the enterprise repo can override
  those by replacing the whole file.
- Many classes have been renamed so that o_form_x_y becomes o_x_y as
  many classes can now be applied outside of form view. These classes
  should not be used in templates anyway.

The commit also changes the DOM of fields so that it is more minimalist
(no useless parent div, etc).

Input elements are not automatically styled anymore, they have to get
the o_input class explicitely. This allows to fix lots of small style
bugs of previous versions (required monetary field had not the proper
style, readonly m2m tags appeared as editable, ...). This also improves
the LESS code.

The editable list view should also completely stop flickering on chrome
and firefox.

The commit also removes the orange outline on list view dirty cells.

The commit also removes deprecated static xml, LESS and other code.

Notice there are still styles to restore/fix and LESS to improve.

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