Use Cargo to build and run benchmarks
This is quite similar to the cargoization of tests in the previous commit. html5ever-external-bench is now gone. benches/tokenizer.rs includes its own test harness that calls through to test::test_main.
Use Cargo to build and run benchmarks
This is quite similar to the cargoization of tests in the previous commit. html5ever-external-bench is now gone. benches/tokenizer.rs includes its own test harness that calls through to test::test_main.
