The pattern to construct `Application` was to use the `try_create`
method from the `C_OBJECT` macro. While being safe from an OOM
perspective, this method doesn't propagate errors from the constructor.
This patch make `Application` use the `C_OBJECT_ABSTRACT` and manually
define a `create` method that can bubble up errors from the
construction stage.
This commit also removes the ability to use `argc` and `argv` to
create an `Application`, only `Main`'s `Arguments` can be used.
From a user point of view, the patch renames `try_create` => `create`,
hence the huge number of modified files.
This currently has exactly one setting: The background colour for card
games. My thinking is, it's better to not have a Settings application
for each individual game we include in the system, since most will only
have a small number of settings, all Settings windows have tabs anyway,
and I don't want to flood the Settings app list unnecessarily.
As for having a single setting for all the card games: it's nice when
things match. :^)
