Bug fix

Mistaken variable name... -_-
fixed configuration to PEN
Improved CategoryExists added FieldExists
fixed wrong references
ini now loads empty categories
improved Request
Improved Callback
Added support for quoted field name

No escape sequences supported... yet
Added check for query string
added support for target attribute
made sure urls are returned using "/" and no "\"

Regardless of operating system the urls use "/", "\" has the risk of
being interpreted as escape sequences.