Redundant node_update_index

node_update_index, an implementation of search's hook_update_index, is implemented in node.module, but an almost identical function is implemented in coresearches/contentsearch.module. Both are called by search_cron in the search module, except the node version can't be turned off. This means that the content search will continue to index content, even if disabled--defeating some of the purpose for using coresearches, as we want to use an alternate indexer (apachesolr) and not waste cron.php time doing the regular search database inserts. Here is a patch we used, which basically just deletes node_update_index() from node.module.