URL connection strings

• Huge issue and pull-request cleanup. Thanks Blain! (@blainsmith)
• #658 Client now parses URL-format connection strings (e.g., redis://foo:pass@127.0.0.1:8080) (@kuwabarahiroshi)
• #749 Fix reconnection bug when client is in monitoring mode (@danielbprice)
• #786 Refactor createClient. Fixes #651 (@BridgeAR)
• #793 Refactor tests and improve test coverage (@erinspice, @bcoe)
• #733 Fixes detect_buffers functionality in the context of exec. Fixes #732, #263 (@raydog)
• #785 Tiny speedup by using 'use strict' (@BridgeAR)
• Fix extraneous error output due to pubsub tests (Mikael Kohlmyr)