The %.*s is very handy to print strings where you have a length, but
there is no NUL termination. It's quite widely supported but at least
one vendor RTOS toolchain doesn't have it.
Since there aren't that many uses of it yet, audit all uses and
convert to a new helper lws_strnncpy() which uses the smaller of
two lengths.
https://libwebsockets.org/pipermail/libwebsockets/2019-April/007937.html
thanks to Bruce Perens for noting it.
This doesn't change the intention or status of the CC0 files, they were
pure CC0 before (ie, public domain) and they are pure CC0 now. It just
gets rid of the (C) part at the top of the dedication which may be read
to be a bit contradictory since the purpose is to make it public domain.
