Weak points:
- alignof
- js problems
Todo:
- make js work with C++ and mozjs-17
- then mozjs-24
- then mozjs-52
- then mozjs-60
- decrease number of warnings
straconcat reads the args with va_arg(ap, const unsigned char *),
and the NULL macro may have the wrong type (e.g. int).
Many places pass string literals of type char * to straconcat. This
is in principle also a violation, but I'm ignoring it for now because
if it becomes a problem with some C implementation, then so will the
use of unsigned char * with printf "%s", which is so widespread in
ELinks that I'm not going to try fixing it now.
