Moves IDataStore to Gambot.Core.
Removes Gambot.Data.

Implementations will be qualified (e.g. Gambot.Data.Redis).
Merge pull request #14 from mohammedh123/feature/fix-idatastore-location-and-visibility

Move IDataStore to Gambot.Core and remove Gambot.Data
Adds a flag for sending action (/me) messages in IMessenger.SendMessage
Adds an IDataStore parameter to IMessageHandler.Initialize