Add a new action reindexall to reindex all the solr index
Currently we have an action named reindex. If the action has a parameter pid, it will reindex the solr index of the specified pids. If there is no pid, it will reindex all solr index.
Even though only the administrator has the privilege, it is still easy to reindex all solr index accidentally, which sometimes is very expensive. We should remove the "index all feature" from reindex and add a explicit action reindexall.