Improve codestyle.
Add clarifying comments.
Use 'movement_gravity' setting and physics override instead of hardcoded value.
Halve number of particles in final 'node dug' burst.
Avoid extremely small, near-invisible particles.
Increase velocity to increase number emerging from within a cubic node.
Previously, night clouds were almost indistinguishable from night sky,
especially since a recent commit that made night sky brighter.
They were lacking the beautiful luminosity caused by being lit by the
permanently-full moon.
When 'directional_colored_fog = false' allow the dawn/dusk cloud
brightness boost to apply through the night too.
Set an identical minimum cloud brightness for when
'directional_colored_fog = true'.
Damage flash is shortened from 0.98-1.27s to 0.25s-0.33s to reduce
player in-game blindness, especially useful for combat situations.
It is also visually more comfortable.
Camera hurt tilt is made slightly shorter to match in duration.
Both flash and camera tilt are now of similar length to a typical
damage sound, such as the one used by Minetest Game which is 0.27s.
The 3 effects become more synchronised and unified.
Previously dungeons > decorations > ores.
Decorations depend on the node they are placed on, and ore types are
increasingly able to place large continuous volumes of nodes, such as
strata. Decorations are increasingly being used underground.
The new order avoids a node being changed by ore generation after a
decoration has been placed on it.
The new order also avoids ores appearing in the walls of a dungeon if
the wall nodes match the local stone node.
Make tunnels wider and use the noise parameters of most other mapgens.
All other underground features are already identical to all other
non-mgv6 mapgens, this final change modernises and improves the tunnels.
Improve item types descriptions.
Add replacements field to fuel definition.
Shorten two headers.
Markdown fixes.
Remove extra example.
Add blank lines after headings.
Linkify section references.
Bracketed section names can be linked when compiled to HTML.
Also, use a better distance calculation for 'collide with objects'.
Fixes the issue of a vehicle occasionally colliding with its own driver,
causing one of the velocity components to be set to zero.
Remove ^ and --[[ ]] symbols.
Fix comment indentation level.
Separate fields with blank lines.
Remove period from single-sentence descriptions, add periods to
multi-sentence descriptions.
Separate inline comments from the code with two spaces.
