src/template/README.md: Add link for shorthand-variable-syntax.
src/reflection.php: Add methods 'implementsInterface' (which returns true if the given $cls implements the interface $iface), 'getImplementations' (which returns all [loaded] classes that implement the given interface), and 'getClassesDefinedInFile' (which, somewhat primitively, attempts to return the names of all classes defined in the specified file).
src/template/: Add support for inheriting from a plain-old PHP class/file (which must implement the Renderable interface); plus some other tidying up.
src/template/: Add support for inheriting from a plain-old PHP class/file (which must implement the Renderable interface); plus some other tidying up.