moved clone method from SoundObject to ScoreObject
added ScoreController; implemented Cut, Copy, and Paste action; fixed issue with adding new layers to layer groups and UI not getting the correct insertIndex
added layer type check
made return null to ignore error
redesigning code to work with Model code rather than UI classes
fix to use List instead of Set, in case of object equals for multiple objects
implemented Paste As PolyObject
fixed getGlobalLayer* methods: increment of SPACER was applied to Y instead of runningY
modified to convert point before building popup menu; removed creation and adding of old ScoreMouseProcessor
made ScoreTimeCanvas and AudioLayersPanel delegate mouse events to parent container manually, as other listeners would interfere; allows setting ScoreMouseListener on the top layersPanel instead of on each LayerGroupPanel