Auto merge of #129 - panicbit:adjust_set_query_from_pairs, r=SimonSapin
Auto merge of #129 - panicbit:adjust_set_query_from_pairs, r=SimonSapin

Adjust set_query_from_pairs bounds

The bounds of `Url::set_query_from_pairs` now match the ones from `form_urlencoded::serialize`.
The previous bounds did not allow e.g. passing in slices or iterators thereof.

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cGuille/rust-url,cGuille/rust-url,servo/rust-url,servo/rust-url