Saving graph file to string, 'e' ought to load a different graph file if the graph_file string changes but haven't tested.
Using ';' and ''' keys to move up and down directorys, enter key confirms the selection, next work on preview- make sure it runs in sep thread?
Drawing connectors before boxes, now can read all port labels.
Fixed bug with descending into lower directory, using cur_sel and checking it now.
Loading a graph segfaults, need to use shared_ptr to clear nodes cleanly?
starting shared_ptr conversion
Tons of shared_ptr conversion, not building yet.  Iffy a little about circular references being handled right, need to test.
shared_ptr conversion compiles, but untested
xFor shared_from_this to work, b must already be owned by at least one shared_ptr."  This means the constructor of an object can't indireclty do shared_from_this() - as some base classes currently do, save those for a separate init function)

Made an init function for all nodes.
Calling base class inits, things look good (didn't try much), tried 'e' to load graph file and got a crash immediately and will debug.
Forgot to add Signal init to base class, now things work much better