* event, website_event, website_forum,
* website_hr_recruitment, website_sale

Website access rights were buggy. The editor assets and website editor
assets have to be loaded together to work so the previous behavior
which only loaded one with the restricted access right was not right.
Also, people which had the "Manager" access right for model like event
or job only got access to creation and edition of those objects if they
had the full access to website access rights.

Now the website module creates the two same groups :
* group_website_publisher: load all editor assets, give access to
page creation for model the user has access (event, job, ...) and
edition of those pages
* group_website_designer: implies the first one and give access in
creation and edition of all pages + access of all website menus

The manager access rights for event, product, jobs, etc now implies
the group_website_publisher group for the user (so that the manager
have the editor assets and editor ui).
Note: some python codes use the group_website_publisher for no right
reason, this has to be adapted.

and return its deferred. This commit makes the behavior consistent with
the `save` method.

* Remove dead code + optimization
* Use Dialog API from web module
* Reorganize files
* Correct buggy $() function for snippet option class
* Add comments

* Fix the snippet parent navigation :

If a page contained a three level snippet structure (i.e A contains
B contains C), when editing the following bug occured :

If B or C was selected first, parenting buttons were correctly set.
But if selecting A then C, clicking on the parent lead to going back
on A instead of going on B.

* Fix snippet thumbnail layout
* Better isolate ui css from themes
* MediaDialog image list : prevent displaying empty attachments
* ...

* Adapt DOM selectors
* Refactore dialog XMLs to have odoo styling
* New editor options (background-position, ...)
* Various improvements

On Firefox, the website page is not completely reloaded after saving or
cancelling. Because of this behavior, the Edit button is kept disabled,
forcing the user to completely refresh the page in order to activate the
Edit button.