Onionskin saving did not work as intended, using it as...
The onionskinning could not be saved like I wanted it to, instead it bugged the purpose for onionskinning. The saved images will be used as backup in %localappdata% folder.
Onionskin is saved now
Onionskin is also saved on save slots and when you load your slot you can continue working like you did before with onionskin.
Copying sprite (not with lasso, lasso was working) with brush to the docker fix
It's now working as intended.
Onionskin update
You now need to move the layer with right mouse button to copy it to a new layer (with onionskin on).
Rearranging layers fixed
Fixed so that you can rearrange layers in the visual layer interface better. Before, they couldn't be rearranged to where they started at.