SP-34: Windows Magnifier: up to 1600 in steps of 25

Windows Magnifier can zoom up to 1600% (instead of 400); the smallest step available is 25 (the size of the steps can be chosen but does not need to be set through GPII).
Merge remote-tracking branch 'cstrobbe/patch-8'

* cstrobbe/patch-8:
  SP-34: Windows Magnifier: up to 1600 in steps of 25