message: Add File::with_options() shortcut
diff: @@ -70,6 +70,10 @@ impl File {
  FileBuilder::new().mode(mode).open(filename)
  }
  + pub fn with_options() -> FileBuilder {
  + FileBuilder::new()
  + }
  +
  /// Returns the file size in bytes (or 0 if the file handle is invalid).
  pub fn size(&self) -> u64 {
  h5get_d!(H5Fget_filesize(self.id()): hsize_t) as _
  