* Define the base colours and brushes.
* import base / system colours.
* test textbox using alias for resource.
* add a fluent theme
* revert default theme
* revert original theme.
* restore default theme.
* remove old accents from fluent theme.
* rename namespaces, etc for new theme.
* make control catalog run again.
* undo textbox work.
* Revert "undo textbox work."
This reverts commit 477665c306.
* add missing fontweight.
* add the UWP base resources.
* Organise the Fluent themes to separate UWP base resources from Fluent resources.
* Add fluentBase dark and light overrides.
* Add xaml files to contain control resources until we get equivalent of ThemeDictionaries.
* undo textbox work.
Make `StaticResource` and `DynamicResource` automatically convert `Color`s to `ImmutableSolidColorBrush`es and add a `ColorToBrushConverter` for use by bindings.
To do this I made `GetResourceObservable` accept an optional conversion function.
If we're selecting a particular tree view item, then materialize and expand the item's ancestors as `SelectionModel` requests children. Only do this if a particular item is being selected, not when an item is selected as part of a range select.
To do this, needed to add a `FinalIndex` property to `SelectionModelChildrenRequestedEventArgs` in order to know if we're selecting a descendent of the item whose children are being requested.
This is a massive hack, but I can't think of a better way to do it with the current `TreeView` implementation.
Dan Walmsley
Nikita Tsukanov
Jumar Macato
aguahombre
Steven Kirk
Dariusz Komosiński
Benedikt Stebner