When the key filter is clicked once, it only displays private link. When it is clicked on again, it becomes red and only public links are displayed. Another click and all links are displayed. The current visibility status is shown in the search banner
Fixes#1030
* Reduce multiple margins (markdown, space between block, etc.)
* Move thumbnails to the right in the same line as the title
* Move edit button as floating to the left
* Move fold/collapse and checkbox buttons as floating to the right
* Add a bunch of HTML ID in the linklist template
Relates to #877
Related to https://github.com/shaarli/Shaarli/issues/877
Plain grey links would lead to think that the link is somehow disabled/inaccessible/private
This slightly improves clarity/usability
* The tag list can be sort alphabetically or by most used tag
* Edit/Delete are perform using AJAX, or fallback to 'do=changetag' page
* New features aren't backported to vintage theme
* Add a checkboxes in linklist which display a sub-header containing action buttons
* Strongly rely on JS
* Requires a modern browser (ES6 syntax support)
* Checkboxes are hidden if the browser is old or JS disabled
* Add API settings in `configure.html`
* Fix textarea autoresize
* Load user.css from data folder
* Move fold/expand all button to the right and fix an issue with already folded items
* Reset datetime display to international datetime
* Temporarilly remove JS login panel (need improvement and integration with the plugin system)
* Body background is slightly lighter
* Fix an issue where thumbnails were hidden by description
* Fix an issue where private orange bar wasn't displayed with thumbnails
* Remove the gradient bar behind titles
* Fix empty bookmarklet name in Firefox
