The main difference was that our implementation was writing
the final line of a series of repeated lines, whereas the
spec says "The second and succeeding copies of repeated adjacent
input lines shall not be written."
Additionally, there was a mistake in the -f flag implementation
causing the number of fields skipped to be one greater than
required.
Flags that rely on counting lines (-c and -d) were
producing results that were off by one. This is fixed
by initializing the `count` variable to 1, which is
consistent with behavior in the main loop, where it
is reset to 1 when lines don't match.
Calls to `read_line` are replaced with `read_line_with_resize`
and `swap`s of StringViews, which assume a consistent location
of the underlying ByteBuffers, are replaced. A test file has
been added for uniq, which includes a test case for long lines.
