Documentation. Greek translation of the Shapes tutorial updated.

Tutorials. German and Greek translations update.

Documentation. Shapes tutorial update (not fully translated yet).

Doc. Shapes tutorial update (see Bug #817907 - Linked offsets regression).

Documentation. Updating fixed Shapes and Advanced tutorials. Adding missing references to the Greek Tracing tutorial.

Tutorials: new Greek translation of shapes tutorial by Dimitris Spingos. Tutorial link update in Greek translation. Translators update.