Lots of bugs fixed.

*  connection error did not properly trigger reconnection logic [GH-85]
*  client.hmget(key, [val1, val2]) was not expanding properly [GH-66]
*  client.quit() while in pub/sub mode would throw an error [GH-87]
*  client.multi(['hmset', 'key', {foo: 'bar'}]) fails [GH-92]
