Fix map-extras

Fixes not only tough-to-understand formatting, but roadblocks spawning
away from roads.  Thanks for the tip, vache.
Reduce amount of roadblocks

Folks have been having problems with them in their current (Bugged)
"everywhere" state, so making them omniprersent on roads might not be so
great either.
Chicken walker minimum range decrease

After John Candlebury helpfully informed me that they can be cheesed
with a rifle.  Should make them a little tougher to game, leastwise at
close range.  Extreme long-shots are acceptable.
Merge pull request #8630 from KA101/map_extra_fix

Fix map-extras