Support single line Template Name comment blocks for theme Templates and apply same cleanup to all header lines. Fixes #8497 props DD32 and Denis-de-Bernardy.

git-svn-id: https://develop.svn.wordpress.org/trunk@11168 602fd350-edb4-49c9-b593-d223f7449a82

wp-admin/includes/theme.php

@@ -133,7 +133,7 @@ function get_page_templates() {
 
 			$name = '';
 			if ( preg_match( '|Template Name:(.*)$|mi', $template_data, $name ) )
-				$name = $name[1];
+				$name = _cleanup_header_comment($name[1]);
 
 			if ( !empty( $name ) ) {
 				$page_templates[trim( $name )] = basename( $template );