Send HELLO/GET_ERROR_MAP before auth
Send HELLO/GET_ERROR_MAP before auth

This allows us the server to send us more detailed information about
failed auth, since we have already sent the XERROR feature as supported.

Change-Id: I6bf2bcd2845b64f6d1c35aa4a8b8d4e4467f9d20
Reviewed-on: http://review.couchbase.org/74614
Reviewed-by: Sergey Avseyev <87f6d5e4fd3644c3c20800cde7fd3ad1569370b3@gmail.com>
Tested-by: Mark Nunberg <dab05a0fe859c5cb93882b2a75a0d613501b07be@couchbase.com>

kojiromike/libcouchbase,couchbase/libcouchbase,kojiromike/libcouchbase,mody/libcouchbase,avsej/libcouchbase,couchbase/libcouchbase,mody/libcouchbase,avsej/libcouchbase,avsej/libcouchbase,couchbase/libcouchbase,avsej/libcouchbase,couchbase/libcouchbase,couchbase/libcouchbase,avsej/libcouchbase,couchbase/libcouchbase,couchbase/libcouchbase,kojiromike/libcouchbase,avsej/libcouchbase,mody/libcouchbase,avsej/libcouchbase,mody/libcouchbase,kojiromike/libcouchbase