peterwolf's Splinecart

## 0.4.13+26.2

- Sleepers follow `/splinecart supports`: wooden ties for `wood`, steel ties for
  `steel`/`metal`, instead of switching by slope. `auto` still uses wood on flat
  segments and metal connectors on climbs.

## 0.4.12+26.2

- Unpowered magnetic track now brakes minecarts to a full stop, including on slopes.
- Detector output from Track Ties no longer feeds back into magnetic track power.

## 0.4.11+26.2

- Track Ties now output a redstone signal when a minecart passes through them.
- Adjacent redstone dust lights up, and comparators read a full signal of 15.

## 0.4.10+26.2

- Smooth spline-to-vanilla rail camera handoff: bake orientation when leaving a
  track follower so first-person view does not twitch.

## 0.4.9+26.2

- Fixed minecarts braking when a spline joins a vanilla rail, including detector rails.
- Fixed minecarts catching rotation and stalling on detector rails next to Track Ties.
- Smooth spline-to-vanilla rail handoff: keep motion continuous and bake camera orientation so the view does not twitch.
- Steel is the default support mode for new tracks (`/splinecart supports steel`,
  also `stal` / `slup` / `pillar`), including command-built and manually linked tracks.
- Steel construction uses a third rail under the sleepers and thin dark-gray
  pillars every 10-15 blocks, narrowed and pulled into the third rail at the top.
- Pillar spacing is measured along the whole spline so chain-drive segments no
  longer place a support at every tie.
- Track Ties can be placed in mid-air one block from the player: under the feet
  when looking down, directly in front when looking ahead, above the head when
  looking up.
- Placement orientation follows look direction: down is floor/horizontal, ahead
  is wall/sideways, up is ceiling/upside down.