OAK-2000: Observation events accessibility not checked correctly
- Avoid NPE when getChildHandler returns null
- Make sure events from multiple paths are not spread across various onEvent calls

git-svn-id: https://svn.apache.org/repos/asf/jackrabbit/oak/trunk@1614591 13f79535-47bb-0310-9956-ffa450edef68
minor improvement: adjust svn:ignore property

git-svn-id: https://svn.apache.org/repos/asf/jackrabbit/oak/trunk@1614593 13f79535-47bb-0310-9956-ffa450edef68
minor improvement

git-svn-id: https://svn.apache.org/repos/asf/jackrabbit/oak/trunk@1614594 13f79535-47bb-0310-9956-ffa450edef68
minor improvement

git-svn-id: https://svn.apache.org/repos/asf/jackrabbit/oak/trunk@1614595 13f79535-47bb-0310-9956-ffa450edef68