馃悰 Fix property values not updated in the property pannel when setting a property to a falsy value when it previously was set to a non falsy value
requested to merge fix/falsy-properties-not-updated-in-ui-when-initial-value-is-not-falsy into develop
This fixes a couple of bugs.
The habillage de fen锚tre and raccourcis clavier properties of a video monitor can now be set. Other initially truthy properties that we would want to set to false will be fixed too. It is now possible to put all value sliders to 0 when the min value permits it.
This also fixes #470