The tag <initialize-to> can be used to control the value
of the output when the component is first enabled. This
controls initialization of the output property and the current
value for internal computation
Valid values are
<initialize-to>input</initialize-to>
set the output-property to the input value
<initialize-to>output</initialize-to>
set the output-property to the output value
<initialize-to>none</initialize-to>
ignore input and output value
Split the former single-file-implementation in xmlauto.?xx into multiple
files and use some OO techniques. Started with documentation to be used
with doxygen.