Check --enable-xxx and --with-xxx options in configure by default

Give an error if an unknown option is specified because this is very helpful
for catching typos which happen quite frequently in practice, considering the
number of options that we have.

To explicitly allow unknown options, i.e. restore the old behaviour,
--disable-option-checking can be used.

configure

@@ -623,6 +623,7 @@ ac_includes_default="\
 #endif"
 
 enable_option_checking=no
+enable_option_checking=fatal
 ac_subst_vars='LTLIBOBJS
 LIBOBJS
 CPPUNIT_CONFIG
@@ -40281,6 +40282,8 @@ $as_echo "$as_me: WARNING: unrecognized options: $ac_unrecognized_opts" >&2;}
 fi
 
 
+
+
 echo
 echo "Configured wxWidgets ${WX_VERSION} for \`${host}'"
 echo ""