Moved all "Increase size" adjusters' protoTrees to the increaseSize
adjuster prototree.
Some member names' renames in order not to collide after merging.
Accidentaly moved the Contrast protoTree to increaseSize. Moved it back.
Only showing the magnifierFollows adjuster, not the magnifierPosition.
PlusMinusAdjuster is not reused so i had to distinguish between textSize
and magnifier.
Brought back the cusros size adjuster.
All now have "range" members which may collide in merging.
Fixed the cursorSize range.
Trying to make the magnifierPosition adjuster work. No go yet...
Brought back previews with no "removeSource".
Fixed the preview in plusMinusAdjusters.
Had to use model.value in cursorSize because it is the only way that the
slider worked correctly (otherwise it lost the saved model value on page
reload).
Had to comment out all PlusMinusAdjuster functionality because it
operated on model.value. Will either refactor this or use Alex's
version.