Add copyright headers to all CZ.NIC owned content

src/common/acl.c

src/common/acl.h

src/common/crc.c

src/common/crc.h

src/common/dynamic-array.c

src/common/dynamic-array.h

src/common/errors.c

src/common/errors.h

src/common/evqueue.c

src/common/evqueue.h

src/common/evsched.c

src/common/evsched.h

src/common/fdset.c

src/common/fdset.h

src/common/fdset_epoll.c

src/common/fdset_epoll.h

src/common/fdset_kqueue.c

src/common/fdset_kqueue.h

src/common/fdset_poll.c

src/common/fdset_poll.h