a76d76eca1 Change `T::from_str(s)` to `s.parse::<T>()` (Jamil Lambert, PhD)
Pull request description:
As mentioned in issue #3234 `s.parse::<T>()` is more idiomatic and produces more helpful error messages.
This has been changed in the main codebase, not including examples, rustdocs, and in the `test` modules.
`use std::str::FromStr;` has been removed where this change makes it unnecessary.
To close the issue it may also need to be changed in the examples and the `test` modules and `contributing.md` updated.
ACKs for top commit:
Kixunil:
ACK a76d76eca1
storopoli:
ACK a76d76eca1
tcharding:
ACK a76d76eca1
Tree-SHA512: 18be389579b5c2d0ba567dfb02b9c8d71c108a749ec5168c60a50e7af9d7f498e364c8f4c0ce1698d960e7d146486899cd10214ebc9c96708ed158a04dfff425