* [ADD][web_editor_background_color] Custom background color picker
This addon lets the user choose a preferred background color when editing some web content.
Works out of the box with `website` and `mass_mailing` addons, although requires none of those.
* [FIX] Avoid clicks removing dropdown menu
This happened specifically in Chrome as demonstrated in
https://github.com/OCA/web/pull/582#issuecomment-287057052.
* [FIX] Use strict equality operator.
Jairo Llopis