Two-way linked support for proxy creation and creators

[docangst-olp]

For proxy cards, the ability to link to one or more cards which can create said proxies; and conversely, from a card which creates a proxy, the ability to link to one or more proxy cards which it creates.

Example:

• Air Yari would link to Yari of Air Experienced as its creator; and would be linked from the latter as its created proxy.