fixes #4110, can input text without 'value' attribute present
Fix layout on google search results.
auto merge of #4113 : payload/servo/issue-4110, r=jdm

The attribute `value` and the underlying model `TextInput` are not connected to each other, so I just pulled the value out of `TextInput`.
auto merge of #4114 : glennw/servo/table-layout-fix, r=pcwalton
Fixes #3962

Bad HTTP responses now have a 0 status code instead of 200 OK.
auto merge of #4128 : jtuchsen/servo/issue-3962, r=jdm

Bad HTTP responses now have a 0 status code instead of 200 OK.
Upgrade rust.
Update xxhash.
Update uuid.
Update string-cache.
Update tls.
Update rust-xml.
Update semver.
Update geom.
Remove a reference to ast::TyUniq.

It was removed in <https://github.com/rust-lang/rust/pull/18752>.
fixup! Update geom.
Update stb-image.
Update html5ever to its master branch.
Remove ty::get call; r=eddyb.
Update cargo.