Consider using ReadWriteLock to protect HubConnctionState in Java client

[mikaelm12]

Currently we're just using a ReEntrant lock when we update the HubConnectionState enum in the Java client. We should considering changing this to a Read Write lock.

[analogrelay]

We need to consider if this needs to be backported. Though if the Java Client is shipping a .1 release prior to 3.0, we can just roll it in to that. Basically I don't want people to have to wait for 3.0 for this fix :).

[mikaelm12]

Do we want this for 2.2.2?

[mikaelm12]

It seems like the actual issue here is that we don't do a connection state check when the invoke method is called. With that information, I'm gonna close this issue in favor for one specific to that work,