Allow terminating gometa on EOL or EOF on standard input.

Change-Id: I71f642cd5c46042fe2ead734570bcc29d4513fa1
Reviewed-on: http://review.couchbase.org/43812
Tested-by: Aliaksey Artamonau <aliaksiej.artamonau@gmail.com>
Reviewed-by: Aliaksey Kandratsenka <alkondratenko@gmail.com>