The three parameter AnalogStick constructor takes an internal name, a
display name, and a default radius argument. The delegated constructor is
the one that calls the ControlGroup constructor, setting the group type,
so passing the group type here is a logic bug.
The only reason this appeared to work despite this bug is because
GROUP_TYPE_STICK has a value of 1, and the default radius value used for
attachment sticks is 1.0.
Better separation of concerns. Relegates `ControllerInterface` to
enumerating input controls, and the new `ControlReference` deals with
combining inputs and configuration expression parsing.
ControllerEmu is a massive class with a lot of nested public classes.
The only reason these are nested is because the outer class acts as a
namespace. There's no reason to keep these classes nested just for that.
Keeping these classes nested makes it impossible to forward declare them, which leads to quite a few includes in other headers, making compilation take
longer.
This moves the source files to their own directory so classes can be
separated as necessary to their own source files, and be namespaced under the
ControllerEmu namespace.
Lioncash