Some small cleanup items
Adding private constructors to a few classes that are static only
Throwing IllegalStateExceptions for things which should not be possible (within the internals of threadly)
Some small spacing changes
Attempt to reduce code duplication with the addition of a very simple "Service" implementation
This is designed to help with anything that has a started/stopped lifecycle.
Within threadly we are able to reduce code duplication within the PriorityScheduler, the SingleThreadScheduler, and the BlockingQueueConsumer.  Some of these changes will not be fully realized until 3.0.0.
Removed deprecated API's for 3.0.0 release
This resolves #97 and saves about 2.5KB in the jar size (which obviously does not include the unit test code).  I also incremented the versions, preparing this for the future 3.0.0 release.