PIVOT-892: add some info (and other small updates) to existing validators, but without deprecating them. Add new validators for Comparable objects and BigDecimal and BigInteger as common cases. Add all new stuff in the test application, to show its usage.

git-svn-id: https://svn.apache.org/repos/asf/pivot/branches/2.0.x@1446274 13f79535-47bb-0310-9956-ffa450edef68