GOCBC-336: Add connection string properties comment
GOCBC-336: Add connection string properties comment

Motivation
----------
The API docs do not detail the connection string properties
that can be passed to cluster.Connect.

Changes
-------
Add connection string properties to comment detailing use of
cluster.Connect.

Change-Id: Ifa6a8db38ed723491aa7112108c21b85e3ed8fca
Reviewed-on: http://review.couchbase.org/97551
Reviewed-by: Brett Lawson <c8c4369773d7d7226e031f0c4af62e3f38a08510@gmail.com>
Tested-by: Charles Dixon <e13bf4498b4994e133fd3586350658dc4a59329a@gmail.com>

brett19/gocb