demo: some options should be disabled when irrelevant

[remcoder]

For instance:

• when rendering lines:

  • tube width should be disabled

• when renedering tubes

  • line width should be disabled

• when not rendering extrusion, disable:

  • line width
  • tube width
  • extrusion colors

• when not rendering travel:

  • disable travel color
  • disable highlight top layer color
  • disable last segment color

• when not drawing the build volume:

  • disable x,y,z size

• [ ] decide whether to grey out or hide disabled options