- fix missing redraw of inventory on wo:add()
- st_puzzle add messages:
- "get_cluster": returns object group of all connected puzzle stones
- "is_complete": returns bool, indicating if cluster is full connected
- add group and positionlist operators:
- obj + grp = group of join of obj with group (same as "grp + obj")
- po .. po = positionlist of the two positions
- polist +/- po/obj/tbl = new polist with offset added to all polist members
- grp1 == grp2 comparison
- negativ grp indices: grp[-1] = grp[#grp], ... grp[-#grp] = grp[1]
- constant definitions:
- N,E,S,W,NE,NW,SE,SW as position vectors
- NEIGHBORS_4, NEIGHBORS_8, NEIGHBORS_CHESS as position lists
