Decimal values from another locations are not handled correctly in NumericTextField

[netonjm]

Xamarin.PropertyEditing/Xamarin.PropertyEditing.Mac/Controls/Custom/NumericSpinEditor.cs

Lines 245 to 255 in f2f3549

	void SetValue (string value)
	{
	if (this.numericEditor.StringValue != value) {
	this.numericEditor.StringValue = value;
	}
	}
	public void SetValue (double value)
	{
	SetValue (value.ToString ());

It's not handling culture infos (european like for example Spain) where NumericDecimalSeparator is "dot" and not the "comma"

I recommend use a.ToString(System.Globalization.CultureInfo.InvariantCulture); for this cases