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.