provide better error message on error with trailing spaces

When there is a trailing space, a useless error message is given via AxisFault.

Assume you should have entered "a" in a field and happend to give "a ", you see

IllegalArgumentException " data=[a ]"

suggestions:

1) subclass IllegalArgumentException with 2 extra fields:

a) the calling class name (generated for the xsd field by wsdl2java), must be handed over to  org.apache.axis2.databinding.utils.ConverterUtil.convertToToken() as a optional 2nd argument

b) a reference to the explanation as per https://www.w3.org/TR/xmlschema-2/#token

 should be set in org.apache.axis2.databinding.types.setValue() when

    !Token.isValid(stValue)

see also AXIS2-5575