Merge pull request NEventStore#412 from kblooie/RemoveCommonDomain

Removed CommonDomain. Deleted old nuget files for mongo and raven

Added PollingClient.ObserveFromBucket(bucketid)

added IPersistStreams.GetFrom(string bucketId, string checkopintToken)
close NEventStore#405

version 5.1.1

Merge pull request NEventStore#333 from damianh/Issue-332

Fixes Issue NEventStore#332

Merge pull request NEventStore#333 from damianh/Issue-332

Fixes Issue NEventStore#332