rustdoc: Fix and improve line break hints with the <wbr> tag

Prevents zero-width spaces from appearing in copy-pasted paths.

Puts line breaks after `::`.

Fixes #16555
Add missing tests for fixed issues

Closes #8761.
Closes #16010.
Closes #13033.
Closes #15094.
regex: Enable test on Windows

Fixes #13725
Remove workaround of #13793/#10872

LLVM assertion error has been fixed recently:
http://llvm.org/bugs/show_bug.cgi?id=18993

Fixes #13793
auto merge of #16450 : klutzy/rust/win-fixme-cleanup, r=alexcrichton

First commit enables regex test on Windows. It was not working at some point (#13725), but it works now.

Second commit removes various FIXMEs regarding #13793, since upstream bug has been fixed.
auto merge of #16556 : pczarn/rust/wbr, r=alexcrichton

Prevents zero-width spaces from appearing in copy-pasted paths.

Fixes #16555
auto merge of #16568 : jakub-/rust/needstest, r=pcwalton

Closes #8761.
Closes #16010.
Closes #13033.
Closes #15094.
snapshots: Register new snapshots.
auto merge of #16571 : pcwalton/rust/register-snapshots, r=pcwalton
libsyntax: Remove the `use foo = bar` syntax from the language in favor
of `use bar as foo`.

Change all uses of `use foo = bar` to `use bar as foo`.

Implements RFC #47.

Closes #16461.

[breaking-change]
Remove 'static analysis'

This has certain implications that are wrong.

Fixes #16299.
auto merge of #16576 : steveklabnik/rust/static_analysis_gate, r=pcwalton

This has certain implications that are wrong.

Fixes #16299.
Improve text of Option.unwrap()

Fixes #9099
Remove innapropriate string mutability section.

Fixes #14948
auto merge of #16575 : pcwalton/rust/import-foo-as-bar, r=aturon

of `use bar as foo`.

Change all uses of `use foo = bar` to `use bar as foo`.

Implements RFC #47.

Closes #16461.

[breaking-change]

r? @aturon
Explain EOF behavior in File.eof().

Fies #16239.
auto merge of #16578 : steveklabnik/rust/gh16239, r=pcwalton

Fies #16239.
auto merge of #16579 : steveklabnik/rust/gh9099, r=pcwalton

Fixes #9099
auto merge of #16580 : steveklabnik/rust/gh1498, r=pcwalton

Fixes #14948