- Added support for textarea and HTMLarea fields + i18n additional labels

(editor Save/Cancel,  YUI Datatable Loading/Error messages, and also column sort tooltips (new in YUI 29.0).
- Added CSS files for the existing two DataTable Templates.  Each file should be added to the corresponding
  template as a CSS Attachment.
- Avoid terminating the editor on Enter.
- Arrange for TAB to save and move editor for next cell also for HTMLarea editor.
- Define classes "wg-dt-textarea" and "wg-dt-htmlarea" + styling for the corresponding cells.
- Commented out handleTableKeyEvent() (reason in the code).
- Implemented a simple workaround to restore the "editor" field (not preserved due to an unknown reason).

www/extras/yui-webgui/build/form/datatable.css

@@ -7,3 +7,15 @@
 .yui-dt-editable .yui-dt-liner {
 	min-height: 10px;
 }
+
+/* displaying the initial blank line in HTMLarea is not useful */
+.wg-dt-htmlarea>p:first-child {
+	margin-top: 0;
+}
+
+/* size of Textarea/HTMLarea cell */
+.wg-dt-textarea, .wg-dt-htmlarea {
+	height: 50px;
+	width: 150px;
+	overflow-y: auto;
+}