Removed the CallableDistributor.  This was created before threadly had first class Future support.  Now that future support is included this could easily be done within code by using a blocking queue of futures, or a hash map of futures.
Added @since tags to the class javadocs (so we know what was included when).  I am defaulting these all to 1.0.0 release, even though many were introduced earlier (just don't want to track when all were introduced)
Whoops, logic error with ! when should be == (yay unit tests)