Added a to() method to PropertyConverter expecting a DefaultConversionHandler.

This variant of the method obtains meta information required for the conversion
(e.g. the date format) from the conversion handler object rather than using an
Object array. The to() method operating on an Object array is going to be
removed after all calling references have been adapted.

git-svn-id: https://svn.apache.org/repos/asf/commons/proper/configuration/trunk@1516572 13f79535-47bb-0310-9956-ffa450edef68