2 commands for speed manager
3 write trivial initial settlement to get data array right
4 write out layout data on crash
5 check that everything in Train and Segment is init'd
6 do lay_train in resolution, or moral equivalent
7 set points under existing trains according to existing movposcomb
9 dunno but maybe before can test
12 things not yet considered at all in safety code
13 coming up against points the wrong way
14 min. curve specifications
17 initialise safety_state with appropriate stuff
21 make safety stop not be estop
22 check safety stop polarity is enough to cope with that