saugns v0.3.6. Redesign. Fix for undocumented feature.

Make parser handling of operator sublists simpler
and more generic, moving specifics to parseconv.

Refactor scriptconv and program.h types.

Make use of '[]' separately from list parameters
function as a generic subscope with few effects.
This feature is still undocumented. Mostly harmless.
(Originally, as '<>', it simply allowed freer use
of whitespace. This was broken by the time of the
2012 releases.)