Allow to use tag like C++ and double check for the same tag slug.

PHP 8 compatibility

See: https://jqueryui.com/autocomplete/#multiple

https://developer.mozilla.org/en-US/docs/Web/HTML/Element/label#using_the_for_attribute

We will change the date format in one go later.

system/htmly.php
- Loads language files from folder lang/
- Sets language settings for date and time format
system/includes/dispatch.php
- function i18n() returns translated strings

Without the step modifier users on Chrome mobile couldn't edit
blogs because the seconds were missing
(hh:mm while hh:mm:ss was expected)

This is my first commit, hope it worked :)

The ported version of Twenty Fifteen and Twenty Sixteen include with the
package. Maintenance and bugs fixes.

Simplify add and edit content. Bugs fixes and improvements.

Use URLify, add pager number, new variable etc.

Prepare release, improvements, and bugs fix  #226

Add new config: static.frontpage = "true" to enable the static
frontpage.

Use the pagedown extra instead of standard pagedown. Adding
sitemap.category.xml