MB-3907 always treat flags as unsigned integer
MB-3907 always treat flags as unsigned integer

Use ctypes library to always treat python integer as unsigned
integer in order to use socket.ntohl

Change-Id: Iebb874c846a76e6a25157d3045d775b94fdfe145
Reviewed-on: http://review.couchbase.org/6618
Reviewed-by: Dustin Sallings <1c08efb9b3965701be9d700d9a6f481f1ffec3ea@spy.net>
Tested-by: Bin Cui <ed18693fff32c00e22495f4877a3b901bed09041@gmail.com>

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