More realistic vehicle collisions.
Merge remote-tracking branch 'origin/master' into Vehicle_Collision

Conflicts:
	map.cpp
	vehicle.cpp
map.cpp
-damage calculation for vehicle-vehicle collisions
-fixed some bugs in line.cpp and vehicle.cpp
-damage for vehicle-vehicle collisions
-changed the equations for vehicle-vehicle collisions (partially elastic collision)
Merge branch 'master' of https://github.com/CleverRaven/Cataclysm-DDA into Vehicle_Collision
-balancing update for vehicle collisions
Merge branch 'master' of https://github.com/CleverRaven/Cataclysm-DDA into Vehicle_Collision
Giving rolling papers to the professions that start with weed.

Cause that's just cruel to give them a bag of grass but no means of
smoking it.
Hockey Mask!
Hockey stick!
Chargen fixes
Optional query is optional (soldering)
Adding sports jersey.
Fix mon_at cache problems (#2756, #2759).
Fixes missing spawns for some of the caseless weapons.
Fix remove_zombie() for dead zombies.

mon_at() returns -1 if the zombie exists in the map but is dead. This was
causing a dead zombie's z_at entry to persist (and then point at a
different, still-living zombie).
Merge some bugfixes.
Fix 5.7mm guns producing nones instead of casings.
Merge sports equipment.