Update 131 - wallpaper and improved copy-paste

- added all the walllpaper plus one of my own design, these are applied (only on the weakside) from the edit panel
- added 90° angle snapping rotation for industrial/fluid parts when not on floors or ceilings
- finally added doorway and window trim
- added extend functionality for spiral stairs
- added a bit more model detail to some switch type devices
- added the missing industrial pipe color
The copy-paste plugin for Rust recently had a big update. Most relevant to fortify were elevators and industrial pipes now being supported. There's a new child entity system for certain parts that required a bit of work.
The follow changes are copy-paste related:
- made elevators and powered water purifiers compatible with the plugin changes
- elevators now correctly snap lower into foundations/floors, replace any from old files before exporting
- fixed elevators connecting to others through floors
- added door controller import with the plugin changes but exporting still needs more work

- fixed the missing color picker for the metal skin override in options
- fixed the wood skin override not applying
- added "device offset fix" to options, the origin position of a bunch of electric parts was changed in a recent Rust update, this fixes older copy-paste files on import
More could be done for copy-paste compatibility like adding a placeholder prefab so less is lost when transferring back and forth. Suggestions are welcome.
I definitely got bogged down with this copy-paste work which is extra frustrating because of the limited time I have for updates these days, would rather be adding cool new features.