Merge remote-tracking branch 'origin/imagefonts'
Merge remote-tracking branch 'upstream/master'
[WIP] Framework for determining part power usage
Adds power requirement for headlights
Adds vehicle alternators and car battery spawns
Merges master branch changes to vehicle parts
Update alternator and car battery PR.

Conflicts:
	data/json/items/melee.json
	data/json/vehicle_parts.json
	data/json/vehicles.json
	lightmap.cpp
	savegame_json.cpp
	veh_typedef.cpp
	vehicle.cpp
	vehicle.h
Tab removal.
Update vehicle battery branch for merge.

Conflicts:
	data/json/items/melee.json
	vehicle.h
Extensive indentation and style corrections in vehicle.cpp.
Merge pull request #3622 from kevingranade/car-batteries-mk-II

Car batteries mk ii