DERBY-896: Allow casts from DATE and TIME to TIMESTAMP

backported change #1568924 from trunk to 10.10.   Backport needed minor
    hand editing to get it to compile in 10.10 because of use of java5
        syntax in the test changes.



git-svn-id: https://svn.apache.org/repos/asf/db/derby/code/branches/10.10@1573815 13f79535-47bb-0310-9956-ffa450edef68