0.7.2:0 — bundle Station Master v0.7.2

Two engine bugs and two rules corrections, plus the Division map redrawn. The submodule pin moves to
v0.7.2 and the version follows it; the downstream digit resets to :0.

- Backing into a cut through a curve's 45° leg no longer couples it back to front, and a crew pulling
  out through one takes its own cut with it instead of leaving it standing.
- The card deck is the published counts exactly, which halves the track and drops two long-standing
  density multipliers — 206 cards to 121.
- Crossing a Mainline card counts the regions printed on it rather than the printed speed, which was
  only ever scenery. Most trains cross faster, slow trains much faster, and Fast/Slow now matters on
  the Hilly card alone.
- The Division map is one row read left to right, so east is always to the right.

GAMES IN PROGRESS DO NOT SURVIVE THIS UPDATE, and this is the first release of which that is true. A
save is a seed plus the moves played, and the deck changing size means a card id recorded under 0.7.1
refers to a different card or to none — so a save stops replaying at its first card.play. There is no
migration because there is no data to move: those moves were made against a deck that no longer
exists, and re-dealing would invent a game nobody played.

It fails safe. The server refuses to resume a save the rules reject, logs which move it stopped at,
and leaves the file untouched, so an operator can put 0.7.1 back on to finish a game that matters.
The release notes lead with this, in all five locales.

Packed and verified as v0.7.2:0 on x86_64.

instructions.md

@@ -43,17 +43,23 @@ changing any of them marks the game **Custom**, which keeps the scoring of the t
 from. The seed, the number of players and the number of Days sit above the type and do not make a
 game Custom — the targets re-derive from them.
 
-**What changed in 0.7.1.** Three things you will see at the table. The **end of a Day now stops and
-says so** — a dialog with the standings, how many Days are left and the combined target, because a
-Day used to turn over inside the phases that run themselves and pass between one click and the next.
-A **Timetabled train may now be thrown away**: toss it face-up to a Department slot and a rival may
-pick it up. That is a New Game setting (*A Timetabled train may be discarded*, on by default) — turn
-it off and a train card can only ever be played onto the timetable. An **Extra is never discardable**
-either way. And a **platform where nothing can be worked now tells you why** — no train for the
-passengers waiting, a train whose card bars Porters, coaches already full, the same-district rule, or
-the Division Yard being out of coaches, in which case it says how many are stranded in the
-Classification Yard and what brings them back. Running out of coaches is part of the game, not a
-fault; what was missing was the explanation.
+**What changed in 0.7.2.** First, the thing to know before you update: **a game already in progress
+will not carry over.** The card deck has changed size, so a game saved under 0.7.1 can no longer be
+replayed, and the server declines to resume one rather than breaking it — it says which move it
+stopped at and leaves the save file alone. If you are mid-game and want to finish it, do that before
+updating, or put 0.7.1 back on afterwards.
+
+At the table, three things look different. **Crossing a Mainline card is quicker, and counted
+differently**: the speed sign printed on the card was always just scenery, and what decides the time
+is the number of regions drawn on it — Plains and Double Track one, Curves and Tunnel two, Heavy
+Grade three unless you have Helpers or Brakeman on it. A train's **Fast/Slow rating only matters on
+the Hilly card** now, instead of adding a Stage to every card, so slow trains in particular get
+across the Division far quicker than they used to. **The deck is smaller and holds less track**,
+matching the published card counts, so building a district is a slower business and the cards you
+draw are worth more. And **the Division map is one row you read left to right**, west on the left and
+east on the right, instead of wrapping around the screen — it no longer shows the inside of anyone's
+district, which is what your own Office map is for, but every train in a district still appears on
+it, with the ones holding an arrival track drawn on the rail and any crew switching drawn below it.
 
 **Leaving, and coming back.** Anyone may leave a lobby, and the host can clear a chair, so a
 mis-join or somebody who wanders off no longer blocks a table that cannot start until every seat is