Turn metal tank into a container.

Also changed volume to reflect holding capacity.
Store fuel on metal tank when removing from vehicle.

Fuel will be stored in a metal tank when it is removed from a vehicle.
Two things to note about this:
    * It will store as much as it can in the tank instead of figuring
      out how much it was holding before
    * The metal will be put on the players inventory so to be able to
      get a reference to it.

These two issues should be worked on in the future.
Use the actual fuel amount in the tank for the refill.

Removing tanks will now remember the amount amount of fuel in them now instead
of being completely filled.
Spawn metal tank on the ground after removal.
remove unnecessary looping

	modified:   mapbuffer.cpp
Barrel-PR-1st-commit

Because a steel jerrycan of whiskey isn't classy enough for my liquor
cabinet. My 1st commit :)
Name change for barrel whiskey

Wanted to have a chance for this to spawn in liquor stores, but not sure
how to get around the already named whiskey
Commas names and liquor

Thank you for the review folks, updated changes/suggestions
added creepy doll
Rename "code_doc/" to just "doc/".
Move all the sources to a src/ directory.
Move lua stuff to "src/lib/catalua/".
Add JsonArray::skip_value for ignoring values when iterating.
Allow raw json data to be extracted from JsonObjects and JsonArrays.
Add empty() method to JsonArray to check if empty.
Tidy some comments.
Add methods to JsonObject to non-fatally set values by reference.
Change JsonDeserializer to take JsonIn, not always JsonObject.
Mark some info getter methods const.
Add constructor for empty JsonObject.

Conflicts:
	json.cpp