Commit 3c9e6c89e7207636c1bdab4ed8118c0c1089d43e made big changes to the
link editor dialog... but also broke many features with it.

Commit 9a1ea6dc08af8b6dc5c5a47277f03f662094d4b2 already fixed some of
them but this commit fixes a bigger one. Indeed, the menu edition
feature was totally broken since the changes. Also, the DOM was messy
which broke form navigation, etc.
This commit also simplifies the LESS which was uselessly big.

Commit a2ae219d4ee283b7e7af84a3e7fa3bb8e0a95f23 fixed the customize_template_get
function(s) which had been modified for the 10.0 web_studio release.
While the fix also reorganized the structure to make it more efficient
and understandable, it promised that the function would be refactored
in master. This is what this commit does.

The customize_template_get route of the website module was also removed
with commit 5a030db3eb77b6d80187f8ae1a64303b2f50391d as it was an useless
duplicate of the web_editor customize_template_get route.

The old route handled two totally different features of odoo: getting
all the page-related views to allow their edition with the HTML editor
and getting the "toggable views" which appear in the "Customize"
website menu. The parameter "full" allowed to determine which one the
route was supposed to do and was useless until website was installed to
add its feature (by extending the route behavior). In both cases, views
informations are returned, only the number of views differs. The
above-mentionned fix already did part of the refactoring by returning
the same info structure for each view in both cases.

Now, the function has been split. The web_editor customize_template_get
route is renamed as get_assets_editor_resources and returns the info the
HTML editor needs to work (the "assets" term is in prevision of the
new LESS editor).
A new website route "get_switchable_related_views" has been created to
return the info the "Customize" website menu needs.
Both use the renamed ir.ui.view function "get_related_views" (old
ir.ui.view customize_template_get function) which now returns a
recordset and not a list of dictionnaries.

Specification
=============

- no boxes around fields
- use regular form style for input fields
- don't split page/URL into two fields, just do one URL field, with autocomplete
- Add alpha, beta, gamma, delta and epsilon color in color selection because they are used in mass mailing and themes also.
- Add a selection option with label "L" inside circle for link.
- Add Color selector for choosing button color
- Remov select2 page selector and used jquery autocomplete on same input
- Fix issue of page search in ir.http

Stop using ugly code for ace editor.

* Really close the ace editor by changing its display property thanks
    to the dedicated do_show and do_hide method.
* Make the common part of ace editors (website, web_studio) consistent
    so that the extensions are really small.
* Do not do RPC to retrieve data already retrieved (now, there is only
    one unique RPC when the editor starts an one RPC per view changed
    on save).
* Fix born-dead code so that the website editor starts automatically
    if the URL contains its associated hash and loads the correct view
* Better handle errors (previous behavior only worked partially and
    only on chrome):
    - Jump to the error line and make it red.
    - Do not open a Dialog with mostly incomprehensible message but
        allow to open it on click of the error marker.
    - Do not save any changed file if one contains an error.
    - Do not allow formatting a file if it contains an error (show the
        error instead).
* Do not use different routes to get the same content (remove the
    /website/customize_template_get route as it returns the same
    content as /web_editor/customize_template_get route). Note: in
    a further commit this route will be refactored.
* In a general way, use consistent method names and behaviors /
    comment the code / lint files / ...
* Open the code to extensions (so that it may later load other data
    than XML).

Note: this refactoring allowed to fix bugs in previous odoo versions
but this commit message will not detail them.

Commit e11f23b701cd061ee2090e506e7ff71cc2ed8c33 split the website
customize_template_get into web_editor and website ones. This split
was not perfect and commit 20861b482a0f84c2946cc14a05648b87b95bdac4
tried to make it work... but did not made it totally and added an
indirect dependency to website module in web_editor...

As the final result is wrong and inconsistent and that the previous
9.0 implementation was already ugly, this was not possible to make
a consistent full-stable fix.

This commit tries to make a fix as stable as possible (the main method
name did not change, the arguments did not change, their purpose is
the same, ...) which makes the code work and be less ugly. However,
the function returns are now slightly different (and JS depends on it).
It returns only valid view information (not header stuff which is not
related to anything and the inherit_id value is now a combination of
the inherit view id and name). Also, a new private method has been
created.

Also, the method contained code which was deprecated since saas-6 but
was never removed (and never broke anything "by chance").

In master these methods will be refactored to make more sense.

Commit 48a1eaf79273fbf40b4b0a55ed28d27382477450 adapt the welcome
message on website so that it fits the page height. But this does
only worked for large screens as the height was forced to main
height... which is smaller than the default welcome message height
on small screen. The fix only had to use min-height instead of height.

Studio altered (probably by error) the default value.
We reset the old default value, and by security, add the params in the call

Following commit 3cbc7ebc4c3e0edb25d1a91dcbf4df163ef6d29e, the bug for customize menu
could have been ignored but as it is an easy fix :

The customize menu is filled after a rpc which is performed on
mousedown on the menu toggle. But in the case the user clicked on the
customize menu before the mousedown handler was attached... nothing
occured. It is possible since the customize menu is rendered but its
JS widget is only attached to it once everything is ready.

Now, the menu is filled on first mousedown or if the menu is already
opened when the JS widget is attached.

In edit menu, search with de demo data /shop, was the 12th results, but limit 9.
We only move the problem to later, but when the user start with the website apps,
it avoid to be lost on first menu creation.