Add tests for DefaultCommand and BypassUndoCommand.
Don't fallback to running as an application command.

If the command isn't registered, do nothing.
Remove unneeded Editor.Keybindings() method.
Rename Keybinding to KeyBinding everywhere.
Add a test for Editor.HandleInput.
Use path.Join for paths
Give Profileentry a capital E.
Added editro.plat function user for loading platform specific settings
Merge upstream