- beds
- boats
- carts
- key/skeleton key
- seeds

All these had on_place handlers that did not allow nodes with
an on_rightclick() handler to be used first (if not using
sneak). This code is taken from the torches mod and applied
everywhere.

This allows all these items to e.g. be inserted into the `frame`
mod's item frames.

If the boat pos is over limit, 'add entity' will not add an entity,
causing 'boat' to be nil.

Boats:
Previously, boats were not added to inventory in creative mode, fix.
In creative mode multiple boats will not be added to inventory.
Add comment.

Carts:
Set speed to 2 if punched by a non-player, to match the effect of a
player punch.
Add comments.

When placing boats, align the boat with the player's yaw.

Align drivers yaw with boat yaw when entering a boat, would previously turn
boat yaw by player's yaw + 90° to the right.

Edited fuels: fences, wooden ladder.
New fuels:
boat, paper, book, dry shrub, stick, vessels shelf, wooden tools,
wooden door, trapdoor, fence gates, farming crops, stairs, slabs, beds.

* Unused variables
* Unused values (assigned to variables, but overwritten before use)
* Defining already defined variables instead of reassigning to them.

Lowering the top surface to be level with the boat top somehow
causes the boat to fall through world if underwater. Revert to
previous position that is needed for correct behaviour

Standing on a boat makes you appear to "hover" over it since this
collision box is way too high. Lower it so that it's low enough
to look normal when walking on top of a boat

If puncher inventory is full, then drop boat

By CProgrammerRU
Also, by paramat:
Slightly raise base of collision box
Improve code style

Boats mod improve y motion. Smaller collision box. Reverse turn with negative velocity only. Smooth turning. Enable underwater higher acceleration

Add spaces around operators in boat mod code, fix a problem with boat staticdata, fix a crash that can occur with boat going over unknown nodes.