[WIP] make the library no_std compatible

[Cxarli]

• Separate the library from the binary
• Add #![no_std] to lib.rs
• Rewrite all own references from std to core or alloc
• Check all dependencies for std usage
• Disable the std feature of crates where possible
• Change dependencies where that is not possible
• • Replace failure
• • Replace fasthash
• • • Get a suitable replacement (See Add no_std support stusmall/murmur3#17)
• • Wait for bincode in [WIP] no_std support bincode-org/bincode#339

A few notes:

• Since we can't use std::collections::HashSet anymore, I have added the hashbrown dependency.
• For better no_std support, I've also updated all dependency versions.
• failure is no longer maintained and uses std, so we will need to switch dependency there.
• fasthash is mostly based on a C FFI, so should be replaced with the pure-Rust murmur3. Since that one also uses std, we will have to patch it slightly.
• LZJDError::Io has been removed since it relied on std::io::Error but was never used. As it's a public enum, we will have to do a major version bump.

[sanmai-NL]

@Cxarli Hi, thanks for your work! I'm the new maintainer. I'll handle the other PR as well, which also touches on the hashing implementation. If you care to finish or update your work, be assured I'll merge it (mostly or completely) within days.