Drop ‘ng’ namespace for scm
Disable swipes if not at min/max X
Add performCloseAllTabs: action method

Closes #808.
Remove ‘InSelectedFolder’ suffix from action method

This makes it more suitable as action for a menu item in the File menu.
Add newFolder: forwarding to document controller
Show key equivalents in file browser action menu

Also change New Document → New File. Such title makes more sense when shown in the main menu.
Rework items and key equivalents in File menu

Adding New File / Folder and Close All Tabs to the menu.