Adding bool property to disable points.

Big improvement of performances when points are not displayed.
Refactoring: separating update radius and color
Objects can now be resized.

Size used to be only updated for new objects.
New property: pause display to stop message processing
Comment harmonisation + bound for some properties
Show/hide Points/Envelopes while display is paused
Adding new class to manage color properties
Code refactoring: avoid mistaking functions name
Fix: color is restored when points are hide/shown