Serialisation/deserialisation of FSMs as FSM transition
matrices.
A FSM may be represented as an transition matrix whose
rows correspond to states of the FSM, and whose columns correspond to
its possible actions (labels on its transitions). A given cell then
represents the transition(s) from some (row) state under some (column)
action, and contains a commaseparated list of integers: the row
numbers of the destination states. (Of course, for a deterministic
action, there's just one, and no comma.) Rows are numbered from 0 and
increment strictly.
