LDEV-1382: If the content repository is called from a webservice, the HttpSession won't exist, so it was throwing a null pointer error. Now it throws a meaningful error.
LDEV-1285 Added two options (buttons) for Optional to the Toolbar. Ready to now configure Optional Activity (canvas class) to manage Sequences within Optionals.
LDEV-1132 Improved robustness of drawing branching activities and fixed problem with activities disappearing on drag-drop to canvas after clearing canvas.
