Use readOptionFile and don't trim aggressively

[som-snytt]

Conventionally, a multiline file means take each line
as an element, no quote parsing required. To support
trailing spaces, do not aggressively trim the input;
that was probably to avoid confusion over a nonempty
line consistently only of spaces; but still do drop
empty elements, that is, a line of zero length.
An empty line is useful to force multiline handling
of a single element. (A single line is split on space.)