TGC: getCell() takes a VisualTreeNode instad of its coordinates
TGC: move edge drawing to a new method
add a new succession strategy "appointment"

Strategy for elected or otherwise appointed titles. Works
by specifying a fixed list of successors.
Title: work with multiple strategies
remove now obsolete FallbackSuccessionStrategy

Functionality now implemented directly in Title.
Title: remove succession strategies from constructor to method

Add a new internal AddSuccessionStrategy() method. Adjust
Storage class.
Succession strategies: remove Title set-accessor and instead
set it in the constructor

Title.AddSuccessionStrategy() is now called in the strategy
constructor. Also adjust parsing.
simplify succession parsing code, remove unnecessary return values
Title: fix reign calculation to be done only on-demand

This can no longer be done in the constructor as succession
strategies are not known then.
add Title.CalculatedReigns property

This only returns reigns calculated so far, without trying to
calculate more. This is especially intended for use by succession
strategies and preference filters, as calling Title.Reigns would
lead to an infinite loop of calling calculateReigns().
pass title to PorpyrogeniturePreference constructor

This eliminates the need for title parameters in the IPreferenceFilter
methods.
Let IPreferenceFilter once again inherit from IComparer<Person>

Now that the title parameters are no longer necessary,
the changes in 3677baf9ca can be reversed.
Refactor ISuccessionStrategy: remove previousReigns parameter

Previous reigns can now be retrieved via the Title.CalculatedReigns
property. Also rename the method to getSuccessor().
Merge branch 'title-strategies'