This reduces memory usage by only storing two lines of the input file at
a time. The current implementation first builds a list of all duplicate
lines ('group') and then decides which lines of the group should be
printed.
Current implementation of the skip fields logic does not handle
multibyte code points correctly. It assumes each code point (`char`) is
one byte. If the skipped part of the input line has any multibyte code
points then this can cause fields not being skipped correctly (field
start index is calculated to be before it actually starts).
- refactor internal version specifications to be ">=M.m.p" (where M.m.p is *already published*)
## [why]
Loosening internal version dependencies decreases the coupling between packages such
that packages can be published in a looser order. It allows the packages to be version
updated and published in tandem (ie, by using `cargo workspace ...`). Once published,
the internal versions can then be updated (again, to an *already published* package
version), as needed.
