Prep for fixing a FindBugs issue in a sub-class
- Add a short-cut to equals for the same object
- Use explicit tests rather than exception handling (should be faster)
- Use all of the fields for the hashCode to improve performance when used in HashTables etc.

git-svn-id: https://svn.apache.org/repos/asf/commons/proper/dbcp/trunk@1557679 13f79535-47bb-0310-9956-ffa450edef68