Rustfmt pass

[kvark]

The settings are mostly default, I find them quite reasonable.

I didn't touch debug_font_data since it just needs to be rewritten with include_bin!.
I didn't touch debug_colors since I wasn't convinced it's worth it. Possibly disable formatting on that file as a follow up.

r? @glennw

---

This change is 

[glennw]

Thanks for doing this! CI is failing due to servo-tidy script checks :/

1.22s$ servo-tidy

Checking the config file...

Checking files for tidiness...

./wrench/src/binary_frame_reader.rs:9: use statement is not in alphabetical order

	expected: std::{mem, process}

	found: std::any::TypeId

./wrench/src/json_frame_writer.rs:10: use statement is not in alphabetical order

	expected: super::CURRENT_FRAME_NUMBER

	found: app_units::Au

./wrench/src/json_frame_writer.rs:15: use statement is not in alphabetical order

	expected: std::{fmt, fs}

	found: std::borrow::BorrowMut

./wrench/src/reftest.rs:8: use statement is not in alphabetical order

	expected: image::{ColorType, ImageFormat}

	found: image::load as load_piston_image

./wrench/src/wrench.rs:7: use statement is not in alphabetical order

	expected: {WindowWrapper, BLACK_COLOR, WHITE_COLOR}

	found: app_units::Au

./wrench/src/yaml_frame_reader.rs:6: use statement is not in alphabetical order

	expected: {BLACK_COLOR, PLATFORM_DEFAULT_FACE_NAME, WHITE_COLOR}

	found: app_units::Au

./wrench/src/yaml_frame_writer.rs:8: use statement is not in alphabetical order

	expected: super::CURRENT_FRAME_NUMBER

	found: app_units::Au

./wrench/src/yaml_frame_writer.rs:14: use statement is not in alphabetical order

	expected: std::{fmt, fs}

	found: std::borrow::BorrowMut

  Progress: 100% (308/308)

Running the dependency licensing lint...

[kvark]

Any issues about the new style?
CI should be passing now.

[glennw]

@bors-servo r+

[bors-servo]

📌 Commit 1fbc96b has been approved by glennw

[bors-servo]

⌛ Testing commit 1fbc96b with merge 1407b1e...

[bors-servo]

☀️ Test successful - status-travis
Approved by: glennw
Pushing 1407b1e to master...