Changing order of fan generation (Cosmetic)

Cosmetic change that will merely make it a bit nicer to look at output
when debugging…
Changed fanout of 0th order variable

0th order variables don’t need to fanout unless they are being used
multiple times whereas others need to be if they are used once.
Added another dup for safety's sake
Fixed bug for simple cases

y’’ = y’ + y would break because obviously the resulting node without
solitary variables is nil, and then it tries to dup nil and use nil.
Now if such happens, we just create a new node out of the variables.
Output *to* fan is now an array

Now it is of the same form as the other outputs.
Added integration connections to layout

Integration connections are now explicitly in the layout output, which
are now handled in fanout. Since they are explicit in layout we no
longer need to worry about them as a special case in fanout, and so
that part of the code has been removed (and finding fans is now simple:
anything with more than one output).
Chaining scripts together

This is easier than reimplementing parts over and over :-)