[WIP][CR]  Boats 

Add to game boats.

A while only inflatable boat (upd: *wooden* also available and can be crafted):

![excursion_3_inflatable_boat](https://cloud.githubusercontent.com/assets/6351438/3489118/f5901d24-0516-11e4-8aa2-95d226f22c8f.jpg)

You can fold/unfold it to carry in inventory and unpack near water. 

Engine - Paddles. It like pedals, but paddles.

Boats can swim by deep and shallow water. On the ground you can grab and drag the boat (or fold it to inventory).

You can fish from boat! Romantics!

![fish](https://cloud.githubusercontent.com/assets/6351438/3489136/2242b36c-0518-11e4-8970-1dcd376280f4.png)

I think the pump is simply attached to the boat.

If you do the pump as a separate object, have to write special  unfold-code that checks whether there he is.