Rename App Methods

- renamed a lot of App methods to CamelCase
- replaced direct public variables with get-/set-Methods

src/Core/Theme.php

@@ -50,7 +50,7 @@ class Theme
 		$a = get_app();
 		$stamp1 = microtime(true);
 		$theme_file = file_get_contents("view/theme/$theme/theme.php");
-		$a->save_timestamp($stamp1, "file");
+		$a->saveTimestamp($stamp1, "file");
 
 		$result = preg_match("|/\*.*\*/|msU", $theme_file, $matches);