Revamping the blocking replies

Renamed "SmartPool" to "BlockingPool" and simplified the thread info handling. More static checks for emission of static molecules. Radical rewrite of blocking molecules code without semaphores and without error replies, simplifying the API. The call reply.checkTimeout() is eliminated: the reply emitters now always return Boolean. New APIs for reply: ReplyEmitter.noReplyAttemptedYet and B.futureReply. Reactions will no longer throw exceptions to unblock waiting calls when errors occur. Instead, a better error recovery mechanism will be implemented. New functionality for thread pools: pool names and thread names for debugging, shorter pool creation syntax, thread group priority API. Thread pools no longer need to be shut down explicitly (although this is helpful if there are thousands of them). Added documentation chapter on Chymyst as an evolution of Actor model.