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

PHP 8 compatibility

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

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.

Add category feature to the core.

Make the tag URL always lowercase and accept case insensitive URL e.g
/tag/htmly or /tag/HTMLy.

Use htmlspecialchars() for title tag and description tag generation.

strip_tags and preg_replace problematic tags.

Trying to add content type: image, video, audio, link, and quote. No
styling yet.

Make HTMLy more flexibel.

Add post draft feature for the blog post.

Styling, performance tweak, and bugs fixes.

FI & Video