-Separate each possible boards (wheel, joystick, skipad, billboard).
-Defined a Driveboard type in Games.xml for each games.
-Due to the refactoring, Driveboard Savestates have changed (a common base data + a specific board data are saved).
-Backwards compatibility with previous save states is maintained.
-Driveboard rom section is no longer required anymore. This disables Driveboard emulation in case the rom is not found.
-Added Billboard emulation (vf3, vs2, fvipers2, von2). 7 segments and lamps Outputs are redirected to Supermodel outputs.
-Changes project to C++ 17 standard.
Removed Ptr_t and ConstPtr_t from public interface, moved config tree builders into their own file, and made them pass by reference and value.
Exceptions can be thrown now on lookup failures.
Removed s_empty_node -- failed lookups in [] operator create a permanent "hidden" child.
Updated comment in NewConfig.cpp.