Partly revert "Appears SwView::SetMoveType no longer really does anything"

This reverts most of commit a50a2111a31e4d9dd5e2659a146e9de8e292de75, where the
-Werror,-Wunused-variable for SwView::SetMoveType's aColor (after
3e8fe4d8e19be2ccd8f5bb898530e2f615a90321 "Remove the Navigator buttons below the
scrollbar in Writer" had removed its use) had erroneously make me think that
SwView::SetMoveType now effectively didn't do anything anymore, failing to note
the

  m_nMoveType = nSet;

part that was still relevant.

Change-Id: I5e43886806533e80e238fef8d836e09e28209b6d