DERBY-5840: Clean up compiler warnings introduced by using Java 5 language features

Fix compiler warning in CursorNode.init() by changing parameter from
List<String> to String[] so that the cast from Object can be checked.

Fix compiler warning in TriggerEventActivator by using a List instead
of an array to store generic types.

git-svn-id: https://svn.apache.org/repos/asf/db/derby/code/trunk@1485984 13f79535-47bb-0310-9956-ffa450edef68