Add translation for "Just another HTMLy user"

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

Simplify add and edit content. Bugs fixes and improvements.

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

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

Update the jquery to 2.1.4 and cleaning up the image upload codes.

Adding image upload to the markdown editor using
jQuery.AjaxFileUpload.js.

Added remove_html_comments function

User role support

Various improvements

Change admin panel.