FARL 0.5.19

• changes to Bulldozer mode:
  • requires a FARL at both ends of the train (direction doesn't matter)
  • removes stuff in front and behind the train
  • doesn't place anything besides the rail it drives on (and removes it afterwards)
• readded Maintenance mode: removes old layout in front of the train and places the new one. You still have to steer it yourself
• removed -root mode, nearly the same results with bulldozer now.
• select a land tile nearby when replacing concrete (less odd looking stripes of land)
• fix concrete being removed when activating bulldozer
• fix error when picking up stone path
• removed unused/old settings
• minor performance improvement (?)