Values in mapping target callback are now always an array

Modules that implement hook_feeds_processor_targets_alter() can specify additional mapping targets. Each target should specify a callback for how to handle the target.
In Feeds 7.x-2.0-alpha8 and earlier it was not clear what kind of value (with which the target should be populated) the target callback would get. It could be a string, integer, array, etcetera. The given value will now always be an array.

Before

<?php
/**
 * Mapping target callback.
 */
function mymodule_feeds_set_target($source, $entity, $target, $value, $mapping) {
  if (!is_array($value)) {
    $value = array($value);
  }

  $delta = 0;
  foreach ($value as $v) {
    $entity->{$target}[$entity->language][$delta]['value'] = $v;
    $delta++;
  }
}
?>

After

<?php
/**
 * Mapping target callback.
 */
function mymodule_feeds_set_target($source, $entity, $target, array $values, $mapping) {
  $delta = 0;
  foreach ($values as $value) {
    $entity->{$target}[$entity->language][$delta]['value'] = $value;
    $delta++;
  }
}
?>