Some files were using ENET_HOST_TO_NET_32 and ENET_NET_TO_HOST_32 without having included the <arpa/inet.h> file beforehand, leading to compiler warnings about implicit declarations of ntohl and htonl.
enet_socket_connect() shouldn't fail with non-blocking sockets.
Removed unused variable.
Sanity check for possible NULL dereference reported by clang's static…analysis.
Added an interface to shutdown().
Fixed typo in the comments.