Add muscle powered as a fuel type.
Add a foot crank as a type of muscle powered power source.
Add a bicycle as a new vehicle type based on muscle power.
Update itypedef.cpp

Make foot crank rarer in preparation for adding it to spawn lists.
Update mapitemsdef.cpp

Added foot crank item to appropriate spawn lists.
Added schoolbus predefined vehicle.
Change schoolbus engine to medium, large was too high-performance.
Add schoolbus to rare vehicle spawn list.
Merge branch 'bicycle' into for-darklingwolf

Conflicts:
	itype.h
	mapitemsdef.cpp
	veh_typedef.cpp
Add bicycle to vehicle spawn list.
Merge branch 'master' of git://github.com/TheDarklingWolf/Cataclysm-DDA into for-darklingwolf

Conflicts:
	mapitemsdef.cpp
Fix indentation in tent iuse function.
Add code to collapse a tent when bashed.
Merge branch 'master' of git://github.com/TheDarklingWolf/Cataclysm-DDA into for-darklingwolf
Move ammo effects to a bitfield in the ammo item instead of filling up the items flag bitfield.
Fixup some damage in reload logic that was preventing gunmods from being reloaded.
Merge branch 'master' of git://github.com/TheDarklingWolf/Cataclysm-DDA into for-darklingwolf
Make add_item() with a quantity recursively create multiple items when the items don't have charges.
Make use of new map::add_item() functionality to simplify code.  Thanks to zpmorgan for pointing out the item stacking problem.