Modules for formHandler

FormHandler is completely object oriented. Every specific part of the
system is contained in a module. These modules can be dynamically added for
a single run. This means performance is good, because modules that are not
used are not loaded or executed.

Documentation of each module needs to be in the file of the module (to
begin with).

A file def.xml is only needed if the module is suitable for dynamic loading
with AUTO_CONFIGURATION

Usage:
There are 2 ways to use a module:
- specify it in the form with the modules option (multiple modules can be
	defined, seperate them with a ':' )
- if the module has a .def.xml file and you have AUTO_CONFIGURATION turned
	on, you can use an option that is required for that module and the module
	will be loaded in automatically.

There are also 2 configuration options that need to be build:
- a configuration file for a specific form that is placed in a subdirectory
	of the script
- a configuration file that is placed in a (sub)directory of the form