Support zooming in the Rotate/Zoom dialog.
Support zooming in the Rotate/Zoom dialog.

Bug: #1252756

PintaProject/Pinta,PintaProject/Pinta,Mailaender/Pinta,jakeclawson/Pinta,Fenex/Pinta,PintaProject/Pinta,Fenex/Pinta,Mailaender/Pinta,jakeclawson/Pinta