YAPfront TO DO
 * handling of default values
 * special handling of binary data (BLOB or BYTEA); don't display, make links instead
 * user may select table to search in extended search
 * introduce request var 'view' to select display of results (list or pretty print)
 * change program flow: parser should better be called *after* all data 
   base queries are completed
 * encapsulate setup data
 * error templates
 * templates for each datafield; lists, pretty prints and forms
   may become fully customizable
 * make it possible to send arbitrary SQL command
 * installation via web frontend
 * maintain internal database tables to store program states or to enable
   dynamic customization
 * XML support (export (import (web service?)))