Remove Lzip because its incorrect, and improve extension comparison

[sigmaSd]

This pr does 2 things:

• Remove lzip (lz) because its was considered by ouch to be lzma but according to https://en.wikipedia.org/wiki/List_of_file_signatures its actually lzip
• Ignore display strings when comparing extensions, this especially useful for inferring because without it file that uses algorithms that can have different extensions wont be detected as equal (ex: lzma)

[sigmaSd]

lzip needs https://www.nongnu.org/lzip/lzlib.html

The sys-crate can easily be generated with bindgen, but I guess we would need a nice rusty wrapper.

[firasuke]

@sigmaSd I've opened #247 and I've been working on:

• the low level crate lzip-sys which is mostly finished, the bindings were generated using bindgen then manually cleaned and modified a bit
• the higher level crate lzip-rs is still being worked on while imitating what bzip2-rs and xz2-rs are doing

Let me hear your thoughts on this!

[sigmaSd]

Hello @firasuke thanks for working on this

Personally I have no experience with those libraries and I see that you have already made some good progress.

I think you would have better chances asking bzip-2 and xz-2 maintainer for guidance.

Otherwise nice work looking forward for it to be used in ouch

[firasuke]

@sigmaSd Thanks!

Actually lzip-sys is done, all that's left is the higher level api lzip-rs which I also have no experience in implementing.

I also tried to get in contact with Alex (lead developer of xz2-rs and bzip2-rs) to no avail.

Perhaps someone with more experience in Rust can give us their thoughts on this.