A new eraser, and a half-page fix

New

• The eraser: a circle shows what it reaches while you erase, in one of three sizes.
• It erases only what it touches. Turn on Whole, beside its sizes, to erase the strokes it touches whole, as before.

Fixed

• Half-page turns: in a song reopened where you left it, turning to that page from the one before turned a whole page at once.