New features:
* maps can be read from files as in #47. The format of the file can be seen in maps/map_template
* added two map files. map1 is the old map that we had been using, map2 is a small map with 4 cranes and no forklifts
* Ad #45 - smooth forklift movement (still lots of bugs, I'll think about it later)
* added some info to README file (ad #23)
Fixes:
* fixed computing the amount of crates per message in ship.py
* fixed checking whether a field is in map bounds in examineSurroundings() in crane.py