I've replaced a few tests with synthetic images and removed a number
that I don't believe are relevant anymore.
I've also removed the #553 test without replacement as I don't know how
to synthesise a replacement and the issue is still open anyway.
Going forward I think we should avoid adding any new "issue" tests and
instead synthesise something suitable in one of the other collections.
Closes#655.
This PR makes 3 changes that together reduce binary size by around 25%:
- Sets lto="fat" in cargo.toml
- Sets panic="abort" in cargo.toml
- Sets location-detail=none in RUSTFLAGS
Closes#571
An unrelated change: I've replaced the zopfli test file with a smaller
one that runs much faster, as well as removing the slow test for
issue-133 which was related to an older alpha optimisation that is no
longer relevant.
