Created double click shortcuts for the treenode panel. Doublick clicking...

... now leads to edit, vote, and statistics panel depending on the session state

Now double clicking the sessions for each node such as pending, open, closed, and ended direct to the appropriate pages. The expert users no longer have to click the edit, vote, end, or statistics buttons. They can just double click the sessions on the node tree side. Some tests are also included for overview panels.

please test