Visualize unsaved changes - Nodes

[MichaelAldrich]

Is your feature request related to a problem? Please describe. Right now it's impossible to know what changes on a layer are unsaved

Describe the solution you'd like Perhaps using the slashes like are used in layer manager to indicate unsaved

Describe alternatives you've considered An asterisk like the layer manager

Potential implementation notes: Store changed nodes (on which layers) in undo commands, the model holds a cache of layers/nodes that changed. If a command finds that its changed nodes are already in the cache do nothing, otherwise insert/pop it from the cache during undo/redo.