Problem: cannot deal with zero-sized msg on input
Problem: cannot deal with zero-sized msg on input

Solution: do not complain if msg is zero-sized; return empty
msg as one would expect.

Also, fixed memory leak in self test.

asokoloski/zproto,zeromq/zproto,bkmit/zproto,jdiez17/zproto,c-rack/zproto,hintjens/zproto,jemc/zproto,sappo/zproto,asokoloski/zproto,jemc/zproto,bkmit/zproto,sphaero/zproto,vyskocilm/zproto,somdoron/zproto,sphaero/zproto,asokoloski/zproto,jdiez17/zproto,zeromq/zproto,zeromq/zproto,hintjens/zproto,jemc/zproto,hintjens/zproto,bkmit/zproto,somdoron/zproto,bkmit/zproto,asokoloski/zproto,jdiez17/zproto,c-rack/zproto,jemc/zproto,sappo/zproto,vyskocilm/zproto,c-rack/zproto,asokoloski/zproto,zeromq/zproto,c-rack/zproto,vyskocilm/zproto,somdoron/zproto,jdiez17/zproto,sphaero/zproto,jemc/zproto,somdoron/zproto,sappo/zproto,hintjens/zproto,c-rack/zproto,jdiez17/zproto,somdoron/zproto,asokoloski/zproto,sappo/zproto,c-rack/zproto,hintjens/zproto,c-rack/zproto,somdoron/zproto,bkmit/zproto,jdiez17/zproto,zeromq/zproto,hintjens/zproto,zeromq/zproto,vyskocilm/zproto,sappo/zproto,somdoron/zproto,hintjens/zproto,sphaero/zproto,sphaero/zproto,sphaero/zproto,jdiez17/zproto,jemc/zproto,vyskocilm/zproto,jemc/zproto,bkmit/zproto,asokoloski/zproto,bkmit/zproto,zeromq/zproto,sappo/zproto,sappo/zproto,vyskocilm/zproto,vyskocilm/zproto