[Therion] Revisiting Breaking extended elevations on specific stations

[Marco Corvi]

i realized i was too naive:
the "principle" of the spanning tree is ok, but it is not enough.

suppose to have five legs at a station
  6-7
  7-8
 20-7
  7-21
  7-45
and some of them belongs to loop(s).
Suppose that the user wants to have 6-7 7-8 together, and 20-7 7-21 together
but the two pairs separated, because of the way loops get extended.
and 7-45 attached to 6-7 7-8 at station 7.

the abstract picture i came up with was to replace a crossway station, like "7"
in the above example, with a complete graph (for 3-leg crossway this is trivial)

to make the story short i think therion syntax needs a way to specify that
6-7 7-8 and 7-45 share station "7" in the extended elevation and 20-7 7-21
share a separate station "7".

marco