current Plug and Play work (SPG/GPL cleanups + 2 new sets)

[mamehaze]

• split a Generalplus Renderer off from the SunPlus renderer, and reduced the SunPlus renderer to just the features supported by the SPG2xx. While the GPL does have similar features, it makes too many small changes to cleanly implement it as a class on top of the SPG renderer, and having it sitting in the same files makes the SPG code less clear. [David Haywood]

new NOT WORKING systems

G6 666 in 1 Handheld [David Haywood, Team Europe]
G7 666 in 1 Handheld [David Haywood, Team Europe]

[mamehaze]

this should get things into a position where I can start to improve the GPL rendering a bit without making a mess of the older SPG implementation.

the 2 VT sets added both boot, but are left as NOT WORKING as I haven't verified the games contained within work well enough yet https://bsky.app/profile/mamehaze.bsky.social/post/3m5c74xrjh222

[mamehaze]

@ajrhacker can you give this a quick look over? I can't really move forward with improving the GPL renderer or other components of those systems until this part is in.