Added mechanism to send KeepAlive messages between sync connections, so that
a message will be sent if time since last time anything has been sent through
the connection is longer than a predefined value.
Fixed bugs in sending/receiving KeepAlive messages.
Merge branch 'master' into keepalive

Conflicts:
	RegionSync/SyncConnector.cs
Make SyncConnector.KeepAliveMaxInterval configurable. Default to 10sec (10000ms).
Change Stream to NetworkStream in GetBytesFromStream and SyncMsgFactory,
and include checking stream.DataAvailable in GetBytesFromStream().
Added SyncConnector to GetBytesFromStream, as an argument for getting the
Connector context.
Revert the changed made to GetBytesFromStream and SyncMsgFactory.