Query alteration done too early

When trying to use apachesolr_autocomplete in combination with a multilingual implementation (inspired from apachesolr_multilingual) we noticed that drupal_alter('apachesolr_query', $query); was called before the query fields were added to the query object.

The impact was that our implementation of hook_apachesolr_query_alter() was not able to alter the query fields on queries coming from apachesolr_autocomplete module. You will find below the patch we used.