Allow english variant overrides

Why are we ignoring en variants?

transliteration.inc:192

      if ($langcode != 'en' && isset($variant[$langcode])) {
        // Merge in language specific mappings.
        $map[$bank][$langcode] = $variant[$langcode] + $base;
      }
      else {
        $map[$bank][$langcode] = $base;
      }

My use case was that there are german names for things being typed into english inputs. Eg 'möll river' which looks better as 'moell river'. I believe this must be true for many cases.

BTW, If I update this module, I'll loose my overrides. Where am I meant to put this?

// Overrides for English input.
$variant['en'] = array(
  0xC4 => 'Ae',
  0xD6 => 'Oe',
  0xDC => 'Ue',
  0xE4 => 'ae',
  0xF6 => 'oe',
  0xFC => 'ue',
  0xDF => 'ss',
);