Allow color families by descendants (WIP)

[martinvanzijl]

This is a possible fix for issue #1.

To use it:

1. Right click on the person and select "Details..."
2. Go to the "Colors" tab.
3. Click the color button.
4. Select a new color.
5. Click "Save".
6. The person and their descendants will have the chosen border color.

Current Issues

• The chosen color is applied, regardless of whether you changed it or not.
• It is difficult to see the color change on the selected person, since it is highlighted with a dotted black line.
• If you add/create a new descendant, the border color is not automatically applied to them.
• If you remove a person from the descendant line, the border color remains on them.
• The border color is not applied to children of the spouse.
• The setting is not saved in XML.

[martinvanzijl]

Below is a demo:

[martinvanzijl]

This is no longer required, now that #2 has been merged.