cherrytree 0.13 issued

• added german language (thanks Sven)
• fixed bugs (thanks Tharsice, Sven*2)
• added menu items to expand and collapse all nodes (thanks Marcin, Tharsice*2)
• added the import/export of a table as a csv file (thanks Tharsice*3)
• added a keyboard shortcut for the enable/disable system tray docking (thanks Andriy)
• improved the bulleted and numbered lists handling introducing actions on multiple lines when multiple lines are selected (thanks Marcin*2)