message: Use root-relative filepath in XML output
diff: @@ -74,6 +74,7 @@ fn write_class<T:Write>(writer: &mut Writer<T>,
  /// Input only tracer data from a single source folder
  fn write_package<T:Write>(mut writer: &mut Writer<T>,
  package: &Path,
  + manifest_path: &Path,
  package_name: &str,
  coverage: &TraceMap) -> Result<usize> {
  let covered = coverage.covered_in_path(package);
  @@ -89,7 +90,7 @@ fn write_package<T:Write>(mut writer: &mut Writer<T>,
  for file in &coverage.files() {
  if file.parent() == Some(package) {
  - write_class(&mut writer, package, file, coverage)?;
  + write_class(&mut writer, manifest_path, file, coverage)?;
  }
  }
  @@ -133,7 +134,7 @@ pub fn export(coverage_data: &TraceMap, config: &Config) {
  _ => manifest_path,
  };
  let package_name = package_name.to_str().unwrap_or_default();
  - let _ = write_package(&mut writer, &parent, package_name, &coverage_data);
  + let _ = write_package(&mut writer, &parent, &manifest_path, package_name, &coverage_data);
  }
  }
  