PIG-3424: Package import list should consider class name as is first even if -Dudf.import.list is passed (rohini)

git-svn-id: https://svn.apache.org/repos/asf/pig/trunk@1515220 13f79535-47bb-0310-9956-ffa450edef68
Merge remote branch 'origin/trunk' into trunk
Merge remote branch 'origin/trunk' into trunk-gd