nomcompile3: Build a set of nomenclature files

This concrete class of AbBind is used when a code relates to a specific taxon and to a specific English name. Note that the English name may differ from that of the taxon. For example, consider this line from an alternate forms file:

albatr Diomedeidae/albatross sp.

However, the line that defines the taxon in the standard forms file looks like this:

f  Diomedeidae/Albatrosses

So in this case the Taxon instance's .eng attribute would be “Albatrosses”, but the StdBind instance's .eng() method would return “albatross sp.”

# - - - - -   c l a s s   S t d B i n d

class StdBind(AbBind):
    '''Bird code bound to a specific taxon.

      Exports:
        StdBind ( abbr, taxon, eng ):
          [ (abbr is the stripped, upshifted bird code) and
            (taxon is a Taxon instance) and
            (eng is the English name from which abbr was derived) ->
              return a new StdBind instance representing that
              code bound to that taxon ]
        .abbr:         [ as passed to the constructor ]
        .taxon:        [ as passed to the constructor ]
        .__eng:        [ as (eng) passed to the constructor ]
    '''