Submit & reset buttons now inside <fieldset>
New method columns_from()

Converts array keys into MySQL column names
['key' => 'value'] returns "`key`"
Broke posts template down into multiple components

Posts template now contains placeholders (%LICENSE% & %COMMENTS_SECTION%) meant
to be used with templates created from what was once there.
With posts template now stripped down, use that for new posts form.

Load necessary templates and set certain attributes so that new_post form will
always match the content of an actual post.

Added <textarea> for description.
Set comments to null before building setion

This way, the placeholder is gone in the event that there are no comments.