Colour the depot couplers by what they connect

Each coupler on the consist strip now shows its state: free, coupled,
multiple-unit, permanent, and at the back whether the end signals go up.
The tooltip gives the code and the connections instead of the drag hint,
and the flyout edits mark the coupler as set by hand and restyle it in
place. The note about 0 on the last vehicle is gone - the colour says it.

StarterNG/startercfg/lang/en.xml

@@ -284,10 +284,15 @@
     <String key="TipSplit">Split the unit into individual cars</String>
     <String key="AppliesToUnit">Shared by the whole unit</String>
     <String key="CouplingUnitRear">Coupler at the rear of the unit</String>
-    <String key="CouplingLastNote">Last vehicle: coupler 0 gets the end signals; any other code couples the train to whatever stands behind it, with no end signals. The starter sets 0 here after every change to the consist, unless you set the coupler by hand; “Auto” always brings 0 back.</String>
     <String key="Join">Join</String>
     <String key="TipJoin">Couple this vehicle with the next one into a single unit</String>
-    <String key="TipReorder">Drag to reorder</String>
+    <String key="CouplerCode">Coupler code: {0}</String>
+    <String key="CouplerFree">The vehicles are not coupled.</String>
+    <String key="CouplerConnects">Connected: {0}</String>
+    <String key="CouplerEndSignals">End of the train — the simulator puts up the end signals.</String>
+    <String key="CouplerCoupledBehind">The end of the train couples to whatever stands behind it ({0}) — no end signals.</String>
+    <String key="CouplerLocked">Locked — not uncoupled in shunting.</String>
+    <String key="CouplerClickToEdit">Click to change.</String>
     <String key="AddVehicle">Add</String>
     <String key="AddMany">Add several…</String>
     <String key="AddManyCount">How many times to add it</String>