Plugins SceneNinja

As requested/suggested by @Goose.k - I've added a "Merge Clothing" option for appearance loading.

When enabled, clothing from the appearance preset will be kept, and clothing currently on the player atom will be added to the preset clothing.

Suggested usage is to create an appearance preset with stuff like eye reflections, nails, makeup, etc. and then let it merge with the existing player atom.

Fix plugin load errors/breakage

Fix issues where the scene would sometimes get frozen on load.
Improve preset/plugin loading timings and pauses for scene load.
Add more checks for gender to determine character is female or male/futa.

Fix more dumb stuff caused by me being dumb...

Improve JSON storage (this will delete settings from V2/1 of the plugin, but fix things as well).

Fix dumb issues caused by not paying attention to what I'm doing...