* Implementation for #6216 - Make number keys select extruder when object treeview has focus
+ deleted unused extruder_selection()
+ Fixed notification after splitting of the solid object
* Follow up 85a10268b9 - OSX implementation
+ Added shortcuts description to the "Keyboard Shortcuts" dialog
* Workaround to use "+/-" and numbers shortcuts on Linux
+ Fixed build on Linux
* OSX specific: fixed a work of keyboard accelerators from numbers on NumPad keyboard
* KBShortcutsDialog: fixed shortcuts for "Preferences" and "Show/Hide 3Dconnexion devices settings dialog, if enabled" under osx
and "Set Printable/Unprintable" and "Set extruder" under Linux
+ OSX specific: Added minimize of the application on "Cmd+M"
* Hot-fix for 6efeb9d6b4
* Removed Linux specific workaround