The OMElementConvertor interface enables customizing the conversion of
XML between Synapse and a script language. Some script languages have their
has no support for those so Synapse needs to handle this itself, which is what
the OMElementConvertor does.
Which OMElementConvertor type to use is discovered based on the file name suffix of
the mediator script. The suffix is converted to uppercase and used as the prefix to
the .js suffix is taken to make the convertor class name
If the convertor class is not found then a default convertor is used which converts
XML to a String representation.