Move PhabricatorObjectItem to PHUIObjectItem, add 'plain' setting for lists.

Summary: Adds plain support for object lists that just look like lists

Test Plan: review UIexamples and a number of other applications

Reviewers: epriestley, btrahan

Reviewed By: epriestley

CC: Korvin, aran

Differential Revision: https://secure.phabricator.com/D6922

scripts/celerity_mapper.php

@@ -101,7 +101,7 @@ $package_spec = array(
     'phabricator-nav-view-css',
     'phabricator-side-menu-view-css',
     'phabricator-crumbs-view-css',
-    'phabricator-object-item-list-view-css',
+    'phui-object-item-list-view-css',
     'global-drag-and-drop-css',
     'phui-spacing-css',
     'phui-form-css',