Apply new clippy lint fixes

The first commit here has some obvious fixes for convoluted code that has idiomatic Rust alternatives. The second commit is for using lifetime elision instead of annotations. I understand this one is a bit more controversion and some projects have opted to ignore this lint instead. Personally I think I'm fine with it, I'd rather see annotations where they are meaningful and need to be included in reading the code to grok it, but if anybody here has issues with that I'm happy to consider ignoring these.