Locked skins now are a specific unlockable type, instead of being tied to the skin's properties.
This has plagued custom gamedata since 2.2 launch. It's extremely obnoxious having to set aside random numbers as dummy unlockables just to ensure that Amy Fang & Metal are unlocked from the start in a custom map pack.
Other changes made to accommodate this:
- R_GetSkinAvailabilities is now created from the list of unlockables set to skin type. (1st skin unlockable defined is (1), 2nd skin unlockable defined is (1 << 1), etc...)
- The "Added skin x" print shows up when loading addons but not at all for the base game, because the previous behavior of hiding based on if the skin was locked would now require iterating unlockables, which felt wrong to do during that stage of the loading process
- I noticed in my test wad that Sonic&Tails would give you Sonic&Sonic out if Tails was locked. I fixed that by making both skins required to show the character select option.
Mods that reserved empty dummy unlockables for Amy Fang and Metal won't have to do anything. Mods that wanted to re-lock them behind different requirements will have to update, but in the future they will not have to be in specific slots. Additionally, now Sonic Tails and Knuckles can also be locked for mods.
(oddly enough, this actually revealed some secret file dependencies previously included via r_things.h! I also needed to include d_player.h in r_skins.h itself it seems)
