Workaround for Classloader-issue

There is a classlaoder-issue with scripts and the plugin-framework.
Currently scripts cannot instanciate FixedPointNumber.
A new helper under the name of "Helper" has been given to scripts with 2 methods
Helper.createNumber(String) and Helper.createNumber(FixedPointNumber cloneme) to work around this issue.
Also the method "clone()" seems not to be visible to scripts for an unknown reason.