api3: Remove lcb_CMDOPTIONS

Let all the options be at the same level, this lets us better optimize
the layout.

Change-Id: I4b81b35c0d68b01d8f2cb3731808d4836ba8e46d
Reviewed-on: http://review.couchbase.org/38926
Tested-by: Mark Nunberg <mnunberg@haskalah.org>
Reviewed-by: Brett Lawson <brett19@gmail.com>