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.
Everything in lws outside esp32 was changed to use lws_snprintf() a while ago.
This fixes a couple of stragglers and removes the preprocessor mangling.
This enables selected things from -Wextra, can't use -Wextra because it is
fussy enough to complain about unused params on functions... they are
there for a reason.
-Wsign-compare
-Wignored-qualifiers
not -Wimplicit-fallthrough=3 ... only on gcc 7
-Wtype-limits
-Wuninitialized
not -Wclobbered ... only on gcc 7ish
fix the warnings everywhere they were found.
