Allow capitals in tag slugs.

controllers/EditTag.php

@@ -120,7 +120,7 @@ class EditTag extends HTMLController
 			$data = $form->getData();
 
 			// Quick stripping.
-			$data['slug'] = strtr(strtolower($data['slug']), [' ' => '-', '--' => '-', '&' => 'and', '=>' => '', "'" => "", ":"=> "", '/' => '-', '\\' => '-']);
+			$data['slug'] = strtr($data['slug'], [' ' => '-', '--' => '-', '&' => 'and', '=>' => '', "'" => "", ":"=> "", '/' => '-', '\\' => '-']);
 
 			// Creating a new tag?
 			if (!$id_tag)