Create: Trackwright

• Train control keys: bind up to five keys to a train's Contraption Controls and switch them from your; sneak and right-click a Contraption Controls block on a train to assign one
• Radius lock: tap R with track in hand to lay exact quarter circles, hold R and scroll to change the radius
• Clear the track bed: sneak and right-click a laid curve with a tool to mine through
• Unbreakable markers (off by default): mark blocks with a honeycomb so drills, saws, rollers and the bore don't break them
• Bored tunnels are now 3 wide and 3 high; hold Left Alt and scroll while looking up, left or right to shape the tunnel.
• The bore leaves track, machines and unbreakable blocks in place, and stops instead of breaking
• A refused bore now says the block in the way and where it is
• Boring, clearing, marking and undo are blocked while a Wand of Symmetry is in your hotbar, and no longer wear an Extendo Grip
• Train drills, saws and rollers no longer break Create blocks, girders or Steam 'n' Rails semaphores
• Rollers get a Terrain option: Reshape only breaks and places the filter block
• Rollers can skip paving where there is no ground below (off by default)
• A bridge with paving in the off hand uses one block per bed block
• Undo keeps the train network whole
• Long connections are drawn once from either end

Known Issues:

• Markers don't stop a saw felling a whole tree or sand falling from above
• Clearing the track bed can't be undone