Filter rewrite never gets applied to values (like 0, 0.0, '', '0') considered empty by PHP

When editing the 'Rewrite filter options', the help text states:

Use this field to rewrite the filter options displayed. Use the format of current_value|replacement_value, one replacement per line. For example:

0|Zero
1|One
2|Two

However, if you do actually try to use the 0|Zero replacement, it won't be applied.

Looking through the code, the following lines in better_exposed_filters_exposed_form_plugin.inc prevent any empty values from being re-written:

if (!empty($search)) {
  $rewrite[$search] = $replace;
}

The check for empty values isn't necessary, as any incorrect search values will be ignored (if (isset($rewrite[$option])) will fail further down on line 943).

I've therefore removed the empty check, so that zero values can be replaced.