Do not reference an obsolete RFC in a new library

Reference the new and improved RFC 7230 instead of the RFC 2616 which it obsoleted.
Merge pull request #9 from brohee/patch-1

Do not reference an obsolete RFC in a new library
Update PartialOrd impl for upstream changes.
Remove depracated "--crate-file-name" argument
Remove depracated "[crate_id]" attribute
Merge pull request #13 from EduardoBautista/remove_depracated_attributes

Remove deprecated attributes
Cargo.
HTTP method.
Fix a couple of erroneous comments.

Thanks to @huonw for finding this.
Make from_vec return the vector if it’s bad.

Thanks to @huonw for the suggestion.
Fix travis to use cargo so deps are around.
How about the nightlies, Travis?
Change #[deny] to #[warn].

It’s such a drag when working on things. To warn is sufficient.

(Ideally there would be something like `--deny warnings` for CI to use.)
Implement Method.into_owned().
Fix incomplete docs for Token.into_owned().
Update method PHF stuff.
Remove the Cargo installation step for Travis.

rustup.sh now does it for us.
Upstream changes around Any and 'static bounds.

``Box<Header> + 'static`` is now ``Box<Header + 'static>``,
``as_{ref,mut}`` is now ``downcast_{ref,mut}``, and we’re all happy.
Change crate type from dylib + rlib to lib.
Workaround to make make/cargo play together.