The configure script no longer recognizes "CONFIG_UTF_8=yes" lines
in custom features.conf files. They will have to be changed to
"CONFIG_UTF8=yes". This incompatibility was deemed acceptable
because no released version of ELinks supports CONFIG_UTF_8.
The --enable-utf-8 option was not renamed.
Either set CONFIG_SM_SCRIPTING in features.conf or pass to ./configure the
option --disable-sm-scripting. Now scripting is also enabled when needed
and not only if some other scripting backend is enabled.
Remove some remnants of SEE scripting backend.