Various bug fixes and improvements.
* Updated CT::Query#set to return self instead of CT::Record
* Expanded CT::Time hour, min, and sec methods to use ctdbTimeUnpack and
implemented the remaining CTTIME_TYPE's in CT::Time.to_s
* Changed CT::Date#month to CT::Date#mon to match other classes
* Added CT::Session#server_name
* Fixed uninitialized constant CT::UnknownAttributeError error and a name
resolution conflict with CT::Time and ::Time when attempting to write lock
a CT::Record.
* Updated test units