Disable scrolling in spinboxes when not desired

Scrolling to change values is not desired in some cases, e.g. the spinboxes for the intrinsic calibration

To prevent accidental changing of the values in such spinboxes, scrolling should be deactivated.

There are essentially 2 methods:

1. Subclassing Q(Double)SpinBox as P(Double)SpinBox and overriding the wheelEvent-method
   • Need to remember to promote the SpinBoxes when they are placed via GUI-Builder/ui-Form
2. Using an EventFilter
   • Need to remember to install this filter on every spinbox (where it is desired)

This problem of changing values involuntarily is also addressed in issue #277 (closed)

NOTE: Also affects the tabs for the coordinate system (3D, 2D)