start integrating upstream queries
start integrating upstream queries

Summary: Use Sarang's upstream lib, for now just do two copies (mysql->vector->item) out of laziness, eventually should pass allocation down if we know the count (perhaps by querying count in advance).

Reviewed By: sarangbh

Differential Revision: D3600579

fbshipit-source-id: 872f1645d117991535db4b0cf375396b787a7c18

facebook/mcrouter,facebook/mcrouter,yqzhang/mcrouter,facebook/mcrouter,facebook/mcrouter,yqzhang/mcrouter,yqzhang/mcrouter,yqzhang/mcrouter