* Painting Exhibit tweaks
- Replaces use of C variable with named variables (e.g. crayon, canvas, current_canvas) in artstuff.dm for readability
- Simplifies painting structure's descriptions and moves wirecutting and persistence tutoring to a notice shown on Examine()
- Adds autodoc for two painting structure vars
- Adds a new desc_with_canvas var to painting structure that's used to set its description when it has a canvas
- Adds a new update_name_and_desc() proc to painting structure called when a canvas is added or removed
- Makes it so painting structures are named based off the painting rather than keeping their generic name
* Changes default names to refer to the "exhibits" as exhibit mountings
- Changes "Secure Painting Exhibit" to "Curated Painting Exhibit" as it's more intuitive
c1af6eb1bd