Sets a zero linger period when close a socket
Sets a zero linger period when close a socket

shilad/ps-lite,xcgoner/ps-lite-new,dmlc/ps-lite,xcgoner/ps-lite-new,dmlc/ps-lite,xcgoner/ps-lite-new,shilad/ps-lite,xcgoner/ps-lite-new,shilad/ps-lite,dmlc/ps-lite,dmlc/ps-lite