Add pre_query filter

I have written an alpha pager for views that I plan on submitting as a new module.

The best way to accomplish this is to add a pre_query hook that gets called in views_query_view. Since there is already a pre_view and post_query hook, I hope that this new hooks will be implemented. Summary of changes below. Full diff attached.

 function views_build_view($type, &$view, $args = array(), $use_pager = false, $limit = 0, $page = 0) {
+  // Call a hook that'll let modules modify the view query before it is created
+  foreach (module_implements('views_pre_query') as $module) {
+    $function = $module .'_views_pre_query';
+    $output .= $function($view);
+  }
  ...
}

I was still able to hook into the views page display without the above change using the hack below. I'm hoping for a cleaner solution.

ALTERNATIVE BAD SOLUTION BELOW

/**
 * These functions are only used if the pre-query hook does not exist
 */

function _views_alpha_pager_init_callback() {
  // NOTE: This is a hack!
  // replace the views_view_page hook with our hook
  // we'll call the views_view_page if we're not using the alpha pager

  // make sure that the menu is built
  /* $menu = */ menu_get_menu();

  // but use a reference to the real menu so we can modify it
  global $_menu;
  foreach ($_menu['callbacks'] as &$menu) {
    if ($menu['callback'] == 'views_view_page') {
      $menu['callback'] = 'views_alpha_pager_page';
      $update_cache = true;
    }
  }
}