It was not clear if our naming followed any kind of rules. In particular,
iconv is a widely used encoding conversion API. We will follow its
naming.
At least 1 returned name was found invalid: x-euc-tw instead of EUC-TW.
Other names have been uppercased to follow naming from `iconv --list`
though iconv is mostly case-insensitive so it should not have been a
problem. "Just in case".
Prober names can still have free naming (only used for output display
apparently).
Finally HZ-GB-2312 is absent from my iconv list, but I can still see
this encoding in libiconv master code with this name. So I will
consider it valid.
Identifiers starting with __ are reserved for the system - user code
(including non-system libraries) must not define them.
A function which takes no parameters is declared with "(void)". In C, an
empty parameter list means that any number of parameters with
unspecified types is allowed, which is not what we want in this case.
Another reason to fix this is that compilers often warn if this legacy
feature is used, which is bothersome for API users.
Additionally, use an opaque struct as underlying type for uchardet_t.
This facilitates type-checking, as it's harder to confuse with other
types, especially in C. This is not strictly a conformance issue, but
still a nice change. Note that this is neither an API or an ABI change.
