Added definition for getl [backport]
Added definition for getl [backport]

I originally put this definition into memcached, but since getl
is an engine specific command I am moving it into ep-engine.

cherry-picked from: 614b7e9ceca5e4baf62767fbe22c8d92e1abab3e

Change-Id: I6544bf846aaf829202ecedce796c711081fc6f47
Reviewed-on: http://review.membase.org/5757
Reviewed-by: Chiyoung Seo <8b279095f11c26cc21045fda5a3e51debb005aa9@gmail.com>
Tested-by: Chiyoung Seo <8b279095f11c26cc21045fda5a3e51debb005aa9@gmail.com>
Reviewed-on: http://review.membase.org/5973
Reviewed-by: Michael Wiederhold <a17fed27eaa842282862ff7c1b9c8395a26ac320@membase.com>
Reviewed-by: Steve Yen <ef850f73f7832052d3c6d9b5ddd3a1716d9a57f1@gmail.com>
Tested-by: Steve Yen <ef850f73f7832052d3c6d9b5ddd3a1716d9a57f1@gmail.com>

zbase/ep-engine,daverigby/kv_engine,daverigby/ep-engine,daverigby/ep-engine,couchbaselabs/ep-engine,membase/ep-engine,zbase/ep-engine,couchbaselabs/ep-engine,sriganes/ep-engine,membase/ep-engine,teligent-ru/ep-engine,couchbase/ep-engine,hisundar/ep-engine,daverigby/kv_engine,sriganes/ep-engine,couchbaselabs/ep-engine,hisundar/ep-engine,abhinavdangeti/ep-engine,abhinavdangeti/ep-engine,teligent-ru/ep-engine,teligent-ru/ep-engine,owendCB/ep-engine,hisundar/ep-engine,sriganes/ep-engine,owendCB/ep-engine,daverigby/kv_engine,teligent-ru/ep-engine,jimwwalker/ep-engine,daverigby/ep-engine,couchbase/ep-engine,abhinavdangeti/ep-engine,couchbase/ep-engine,zbase/ep-engine,owendCB/ep-engine,couchbaselabs/ep-engine,couchbaselabs/ep-engine,sriganes/ep-engine,zbase/ep-engine,hisundar/ep-engine,membase/ep-engine,couchbase/ep-engine,abhinavdangeti/ep-engine,jimwwalker/ep-engine,jimwwalker/ep-engine,daverigby/ep-engine,zbase/ep-engine,abhinavdangeti/ep-engine,jimwwalker/ep-engine,membase/ep-engine,owendCB/ep-engine,daverigby/kv_engine