Moved all classes in com.mongodb.codecs into com.mongodb and made them package private.
Making ServerDescription.toString() output more concise by only including relevant fields.
Inlined a private method that is only used once. Including cluster description in exception message when no server can be found for the given selector.
Grabbed ConcurrentLinkedDeque from jsr166x (http://gee.cs.oswego.edu/)
Using ConcurrentLinkedDeque in ConcurrentPool so that we can have stack-like behavior.