asix-sigma: style nits, devc in routine signatures, long text lines

Move the 'devc' parameter to the front in routine signatures for the
remaining locations which were not adjusted yet. Reduce indentation of
continuation lines, especially in long routine signatures. Try to not
break string literals in diagnostics messages, rephrase some of the
messages. Massage complex formulae for the same reason.

Whitespace changes a lot, word positions move on text lines. See a
corresponding whitespace ignoring and/or word diff for the essence of
the change.