Merge pull request #16 from KevinW1998/master

Implement now first working operation with undo/redo: remove-operation
Separated Scene / added template for add new items
Language menu template / hot keys for Undo/Redo
small changes
Stored remove actions and Undo/Redo for blocks and BGO
Merge pull request #24 from Wohlstand/master

Merge to Update 24