Also add a note that you should not use the old build system. (It's only
kept because of the "asshole maintainer" rule: no matter how broken or
pointless someting is, as long as you're the maintainer and want to keep
it, it stays in the repo.)
For now, it needs to be explicitly selected. ENCA is still the default.
This assumes uchardet returns iconv names. This doesn't seem to be
always the case, and the result are lots of iconv errors. So
explicitly check for this situation, and print a warning if it
occurs. It's entirely possible that uchardet support is actually
useless, because names are not necessarily iconv-compatible (but
uchardet doesn't seem to document whether it attempts to return
iconv-compatible names if possible).
Fixes#908.
It's useless, and creates a bogus warning in subprocess-posix.c.
Since I don't know which compilers might have it by default, just change
it to -Wno-redundant-decls.
