Layout menu should be more flexible

[aylward]

The list of layouts doesn't work well as more layout options are being added.

Perhaps using nested menus (just one level of nesting) will help.

Below, the numbered items are the top-level menu items, and the bulleted items below them are the submenu options.

1, Single Slice View
- Axial
- Coronal
- Sagittal
2. Focused View
- Axial
- Coronal
- Sagittal
- 3D
3. Quad View
4. Oblique View

[aylward]

Menu only shows
Single
Focused
Quad
Oblique

Then in single/focused view there is an additional menu

• sub-views in focused view are automatically updated.