src/template/: Rename misspelled 'saveExpandendTemplate' to 'saveExpandedTemplate'.
src/template/inheritance.php: Remove old, commented-out function.
src/web-client/html-parsing.php: Add 'TODO' item.
src/template/token.php: Add function 'isOfType'.
src/template/shorthand-php.php: Make simplified if-else syntax work again.