Made property_string_list and property_string accept AsRef<str>

[jounathaen]

Summary of the PR

Currently, property_string_list only accepts Vec<String>, which requires me to copy all values I want to pass to a device tree node. With this change, property_string and property_string_list accept any parameter that is AsRef<str>, making it usable with both String and str.

This should be backwards compatible, except for cases where it could now be unambiguous (like the fdt.property_string_list("strlst", vec!["hi".into(), "bye".into()]) that was in a test.

Requirements

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• Any newly added unsafe code is properly documented.

[danielverkamp]

Thanks, the change looks like a good idea overall to me.

I think AsRef<str> alone should be sufficient, which might make this a little more flexible - with that tweak, it should be good to go.

[danielverkamp]

nit: for consistency, it might be nice to keep the hex digits consistently lowercase - although I guess the ones in the comments are uppercase, so it's already not really very consistent :)

[jounathaen]

True. There are still some uppercases left, but these were not introduced by me 😉