Landrok

Since #35 , WebFinger call supports non-filled attributes. In some cases, these should be required (Ontologies, authentication, translation from username to URLs). Some server configurations may be implemented.

When a template is modified, a static callback emits this warning: `Warning: preg_replace_callback() [function.preg-replace-callback]: Requires argument 2, 'self::single_path_replace', to be a valid callback`

Related to https://github.com/stdtabs/phptabs/issues/7#issuecomment-420574426, some more recent versions of Guitar Pro file formats should be supported.