PIVOT-895 - add SuppressWarnings("unchecked") so ant builds won't generate many warnings.
Note: keep them even if in eclipse it say they are unnecessary (depending on eclipse Java Compiler Warnings settings).

git-svn-id: https://svn.apache.org/repos/asf/pivot/trunk@1519637 13f79535-47bb-0310-9956-ffa450edef68