ListEditor could do with KeepVoid property

[Bruce Steers <bsteers4@xxxxxxxxx>]

I just had to modify a ListEditor as i realized it was removing blank lines
if i clicked on them.

The ListEditor was being used to show/edit lines of a Settings.conf file so
i didn't want it to auto-remove blank lines.

It seems hard coded to do that, making it's usage kind of limited.
so i imported it and simply added a ListEditor.KeepVoid property.

So now "If Not GetParent().KeepVoid And If Not txtData.Text Then" removes
lines.
Respects
BruceS