Mirror selection Mode :
This mode allow to mirror a points selection on any axis and to fix bad symetry
This allow to do a symetry on selection, even if the object is not centered.

NB : this function may be slow

	Starting Shape
	Select some points
	Choose your mirror axis
	Result
	The sphere has been a bit twisted
	Select some points
	Select your axis
	Bad selection... the symetry is broken
	Increase the mirror threshold value
	Better now :) But the symetry is still broken
	New cleaner shape, to see what will happend
	Jitter some points
	Select points
	Activate the "Fix Mirror" option And set also a good threshold value
	Bad points are moved to correct the symetry
	These functions can also be done on a non-centered shape
	Simply use the "Use object center" Option