Wagtail-cjkcms

Fixed
- Fixed problems on some websites resulting from renaming navbar_search.html. Restored the previous template file name.

Fixed
- Fixed regression bug causing menu items to be hidden. This required me to fully remove
check for the deprecated menu items visibility options.

Removed
- Removed deprecated menu visibility management via visible_for field in NavBlocks
CMS blocks are JSON-based, and ignored in migrations, so If we removed the field in block defintion, this would not cause the data in database disappear. As a result we might have blocks in various websites which are strangely invisible to users, even if nothing is set in the visible block definition. So for safety, a new setting has been added: CJKCMS_NAVBAR_SHOW_VISIBLE_FOR = False. Switch it to True to restore visibility of that block component, if you have problems with any websites. For security, implementation of the visibility checks in templates (can_show_item value.visible_for ) was NOT removed from code.
- Corrected issue with fixed top navbars. Important - this changed some implementation details (e.g. css styling), so check your site if it uses fixed navbar

Added
- "countdown" content block using VincentLoy's library. See https://vincentloy.github.io/simplyCountdown.js/ for more info
- added themes and tests for the "countdown" block

Added
- Support for breadcrumbs per-page visibility
- breadcrumb_title page property for all CMS pages, choosing new "breadcrumb_label" field or page title if new field empty
- Added new templatetag with tests: first_not_empty which returns first not empty argument from the list, e.g. {% first_not_empty var1 var2 var3 %}

Fixed
- Update malformed robots.txt file