Huge refactoring - the code now host multiple pools together

* got rid of singleton miningmanager.cs - all pools have their own instances of stuff like, stratumserver, stratumservice, jobmanager, sharemanager and minermanager.
* got rid of daemon-manager as we don't need it. pool instances will manage their daemon connections on their own.
* moved block & block-header serialization code to src/CoiniumServ/Core/Coin/Helpers/Serializers.cs.
* extra nonce and job counter are no more static classes. each pool host their own instance and track their own data.
* stratum-service is no more a static class, each pool instantiates it's own .