MCE Views: Add alignment styles for generic views.

Adds `alignnone`, `aligncenter`, `alignleft`, and `alignright` by default.

see #21390, #21812, #21813.


git-svn-id: https://develop.svn.wordpress.org/trunk@22219 602fd350-edb4-49c9-b593-d223f7449a82

wp-includes/js/tinymce/themes/advanced/skins/wp_theme/content.css

@@ -161,6 +161,23 @@ img.wp-oembed {
 	box-shadow: none;
 }
 
+.wp-view-wrap.alignnone {
+	display: block;
+}
+
+.wp-view-wrap.aligncenter {
+	display: block;
+	text-align: center;
+}
+
+.wp-view-wrap.alignleft {
+	float: left;
+}
+
+.wp-view-wrap.alignright {
+	float: right;
+}
+
 .wp-view-wrap .overlay {
 	opacity: 0;
 	display: block;