Added "url type" to the ::URLHandler "missing template" warning

Tells the user what kind of template the renderer was looking for, easing
troubleshooting.
Verify that the template TYPE is valid

If it isn't then installation will be aborted
Converted to using DBIC directly (greatly improves speed)

Added support for populating some additional field (--populate-fields)
Added --max-title for limiting article titles
Added --min-body-paragraphs for setting the minimum number of paragraphs in the body
Added --max-body-paragraphs for setting the maximum number of paragraphs in the body
Added caching to LzArticle's getField
Made LzCategory serializable
Added a category data source