Don't use ns_config:eval for ns_bucket:get_bucket{,s}.
Don't use ns_config:eval for ns_bucket:get_bucket{,s}.

Using ns_config ets table is faster.

Change-Id: I8e716605c1fa4ffce1b6d233ddca317ce76285c6
Reviewed-on: http://review.couchbase.org/48041
Tested-by: Aliaksey Artamonau <3c875bcfb3adf2a65b2ae7686ca921e6c9433147@gmail.com>
Reviewed-by: Artem Stemkovski <15a0730a27c69f62ab86f2b6c639fca202166c02@couchbase.com>

ceejatec/ns_server,nimishzynga/ns_server,membase/ns_server,nimishzynga/ns_server,ceejatec/ns_server,membase/ns_server,mschoch/ns_server,membase/ns_server,ceejatec/ns_server,ceejatec/ns_server,mschoch/ns_server,mschoch/ns_server,membase/ns_server,ceejatec/ns_server,ceejatec/ns_server,membase/ns_server,nimishzynga/ns_server,nimishzynga/ns_server,mschoch/ns_server,membase/ns_server,mschoch/ns_server,mschoch/ns_server,nimishzynga/ns_server,nimishzynga/ns_server