/mutable_appearance should have more vars than /image + opacity

[Kaiochao]

SpacemanDMM/src/dreammaker/builtins.rs

Lines 941 to 942 in 35915f7

	mutable_appearance/parent_type = path!(/image);
	mutable_appearance/var/opacity; // inherited from /mob according to the docs

[SpaceManiac]

like what

[Kaiochao]

Well, just from difference in what the docs show for vars (mutable_appearance) and vars (image):

/mutable_appearance vars that /image isn't documented to have:

• density
• desc
• gender
• invisibility
• layer
• luminosity
• animate_movement
• mouse_over_pointer
• mouse_drag_pointer
• mouse_drop_pointer
• mouse_drop_zone
• mouse_opacity
• name
• opacity (got this one already, nice)
• screen_loc
• suffix
• verbs
• vis_flags

/image vars that /mutable_appearance isn't documented to have:

• loc
• override
• render_source
• render_target
• vis_contents
• x
• y
• z
• type
• tag
• parent_type

[SpaceManiac]

The docs have this to say:

The /mutable_appearance datum is technically a descendant of /image, but this is only for convenience, and should not be relied on for any other purpose as it is subject to change in future versions.

I have to strike a balance between implementing DM as documented and implementing DM as actually used. In this case I will be making available the same set of vars on /image and on /mutable_appearance that the DM compiler does.