Upgrade dependencies and remove deprecated failure, which causes GitHub security alerts

[AdrianEddy]

• Migrate from failure to thiserror
• Update most dependencies to recent versions
• Migrate from r#try! macro to ? operator
• Fix warnings

There were also security alerts for crossbeam 0.7 used by qutex. I see that dependency was updated on git, but not published to crates.io, so I used git dependency in Cargo.toml. It would be great if you can publish updated qutex so we can just use the new version here.

One last dependency that was not updated is futures 0.1. There were many changes in the API and I also see qutex can use 0.3 beta. I think we can separate this one for now - update all other dependencies, and take care of futures in ocl and qutex separately.

This PR also includes changes from #201 and #199 as they were dependency updates too, as well as #183, #170, #171 for warnings. Also after this PR is merged #178 can be closed.

It would be great if you could merge this PR, it causes GitHub Security alerts on dependent projects.

[c0gent]

Looks great. Really appreciate your help.

Qutex is published.

Thanks again and let me know if anything else needs my attention.

[AdrianEddy]

amazing, thank you very much! If you could just replace qutex = { git = "https://github.com/cogciprocate/qutex.git" } with qutex = "0.2.4" in ocl/Cargo.toml and release updated ocl to crates.io that would be great!

[AdrianEddy]

also sorry I missed, PR #179 can also be closed, it's included here as well

[c0gent]

Done. Thanks again!

[AdrianEddy]

Also one more thing, it looks like the ocl-core-vector on crates.io differs from the git version, and it contains dependency to num 0.1, you can see this here: https://crates.io/crates/ocl-core-vector/0.1.0/dependencies (and verify here https://crates.io/api/v1/crates/ocl-core-vector/0.1.0/download )
The version in git depends on num-traits 0.2 instead, and it doesn't pull legacy dependencies.

Sorry to bother you like that but it would be really nice to also update ocl-core-vector on crates.io to get rid of that old dependency

[AdrianEddy]

@c0gent any news on releasing the updated ocl-core-vector to crates.io? This one produces one last warning on dependent projects

[c0gent]

Sorry for the delay. Published!

[AdrianEddy]

Thank you very much! Now everything is looking good 👍