Remove conversion from locale to utf8 from public API

Remove conversion from locale to utf8 from public API

Emit fatal failures on locale to ACE encoding

Separate idnout support, disable it for libidn2 < 2.0

Add custom path to libidn. Leave default path for multilib support.

Allow turning off IDN input processing by dig option

Improve documentation, fix support in host

Fix configure changes to adjust help text

Use strlcpy with size guard

Improve IDN variants choosing. Fix idn2 function name.

Remove immediate idn_locale_to_ace and idn_ace_to_locale.

Signed-off-by: Petr Menšík <pemensik@redhat.com>