Converting existing automated movement to use a subsystem.

[MistakeNot4892]

Description of changes

• Adds SSautomove to replace walk_*() inbuilts (and eventually the direct unmanaged AStar() calls that bots are using).
• Adds movement intent to simple animals.
• Renames vars on simple animals (speed to base_movement_delay and turns_per_move to turns_per_wander) for clarity.

TODO

• [x] Get the basic system working.
• Add movement intents to bots. why did I put this on the todo
• [x] Work out why animals can't change to run intent.
• [x] Implement avoidance to replace walk_away().
• [x] Go back over simple_animal values and fold base_movement_delay into movement intent or automove metadata where possible.
• [X] Check simple_animal use of step() in case it can be tied to this system.
• Maybe get bots using this system as well. Probably something for another PR.
• Get meteors working.
• [x] Maybe just swap obj back to walk_to().

Why and what will this PR improve

Condenses various movement values for simple animals and makes them use movement intents properly.

Authorship

Myself, with some reference to how /tg/ handles their automovement for ideas.

Changelog

Nothing player-facing.

[MistakeNot4892]

Got walk_to() and walk() functionally replaced, will work on walk_away() in the morning.

[MistakeNot4892]

Current big issue, automove ends after one step. No runtimes, just stops moving and sits there like a lemon.

[MistakeNot4892]

• Spiders are working. They hunt you down, attack you, and continue attacking you while visible, and change target if you disappear.
• Deer are working, to an extent. They flee appropriately.

Main thing missing from this implementation versus walk() is that the mob will only ever move in the direction away from you, they won't try to skirt around obstacles at all. I have logic in place that should also try diagonal moves if the cardinal move fails, but it does not work for reasons that escape me. :(

[MistakeNot4892]

Added a movement delay reset function that has resolved the issue, all seems more or less equivalent now.