Avoid erroneous 'Could not cancel' warning produced by cache tasks

This closes #3
For added safety, install a connection state listener and attempt to recreate the node on RECONNECT
Upgrade to latest versions of dependencies/plugins (include ZK 3.4.6), fix longstanding problems where JUnit Asserts were accidentally used, removed some bogus deps, fixed up the poms, etc.
Removed 'optimization' to prevent extraneous queue creation. I don't understand what it was supposed to do and it seems unnecessary. It's also the cause of the test failing.
Merge branch 'master' into CURATOR-96
Added optional leader selector support
Expose leader path to ChildReaper
Merge branch 'master' into CURATOR-96

Conflicts:
	curator-recipes/src/test/java/org/apache/curator/framework/recipes/locks/TestReaper.java
Removed junit dep
doc refinement
getZooKeeper() should fail if the instance has been closed
make ChildData constructor public for access from unit tests and such
Fixed some places where background callbacks weren't checking the event result code
Merge branch 'master' of github.com:tedpearson/curator into CURATOR-102

This closes #4
Major issue! Thread that was canceled due to CancelLeadershipException was getting re-used and thus exiting immediately. Instead, a new thread from the pool should be used
Fixed a slew of javadoc errors
latest apache parent pom
maven-release-plugin v 2.5 - fixes blocker bug
[maven-release-plugin] prepare release apache-curator-2.4.2
[maven-release-plugin] prepare for next development iteration