Incorrect error message on authentication failure

Incorrect message when user doesn't have access to bucket.

1. Implicit
   cb = Bucket('couchbase://127.0.0.1/bucket-legacy-username_as_bucketname',password="password")
2. Explicit
   cb = Bucket('couchbase://127.0.0.1/bucket-legacy-username_as_bucketname',username="bucket-legacy-username_as_bucketname",password="password")

Both of these return a generic error instead of authentication failure:

Case 1:

I just removed data-reader and data-writer access from the user, it should have failed authentication and NOT reported a generic error. (Python client attached for testing). So user absolutely has no access to the bucket at all

couchbase.exceptions.CouchbaseError: <RC=0xA[Generic error], There was a problem while trying to send/receive your request over the network. This may be a result of a bad network or a misconfigured client or server, C Source=(src/bucket.c,785)>

Case 2:

User has access to the bucket e.g. Query access but not RW access. Again error does not report authentication/permissions but aburpt connection closure.

couchbase.exceptions.LCB_0x2D (generated, catch: CouchbaseNetworkError, CouchbaseTransientError): <Key=u'first', RC=0x2D[The remote host closed the connection], Operational Error, Results=1, C Source=(src/multiresult.c,309)>