Pack in a copy of libev-4.15

server/Makefile

server/libev/LICENSE

server/libev/README

server/libev/config.h

server/libev/ev.c

server/libev/ev.h

server/libev/ev_epoll.c

server/libev/ev_kqueue.c

server/libev/ev_poll.c

server/libev/ev_select.c

server/libev/ev_vars.h

server/libev/ev_win32.c

server/libev/ev_wrap.h

server/libev/event.c

server/libev/event.h