Started a new method

My first attempt was based on having the parent node tree stored in the database with each category. Now I'm doing it the right way by using nothing but the parent node ID number and not relying on a tree. Also, the JS wasn't using the updated AJAX API.
Contains two bug fixes
Contains bug fixes
Almost done with Categories!!

Admins can now add and delete Categories, users and filter logs by Category. All that's left is the ability to add logs with Categories.
Restyled filter input for consistancy
Almost finished with the category feature

Admins can add/delete categories, users and search categories. All that's left is the ability to add logs with new categories. Also, eventuall the ability to edit categories.
Database driven category support is now completed
Admins can now edit category descriptions
Admins can now set a slogan that will appear below the website title
Edited install for new settings table and slogan
Styled slogan text