Remove wrong include directive.
Move VSP_DECLARE_PRIVATE and VSP_DEFINE_PRIVATE into its own header. Fix private class declaration in DegenGeomScreen and CompGeomScreen.
Revert: Factor out common double widget input device. All double input devices have settable range, since a Q[Double]SpinBox does full input validation. This change was invalid since it didn't take into account the semantics of GuiDevice inputs. (reverted from commit 3446a844eccd85fde2a9d47421b0dd31ad406f73)
Fix behavior of Qt gui devices: block update signals when values are changed programmatically.