* automake.mk: Add new file.

* formats/360.sh: New test.

* str.c (ds_read_stream): Change return value semantics to be more
useful.  Update all users.

* data-reader.c (struct dfm_reader): New member `block_left'.
(dfm_open_reader): Initialize block_left.  For FH_MODE_TEXT, open
the file in text mode.
(read_error): New function.
(partial_record): New function.
(try_to_read_fully): New function.
(enum descriptor_type): New enum.
(read_descriptor_word): New function.
(corrupt_size): New function.
(read_size): New function.
(read_file_record): Implement new modes.
(read_record): Now take care of tracking line numbers here.
(dfm_reader_get_legacy_encoding): New function.

* data-writer.c (dfm_put_record): Implement new modes.
(dfm_writer_get_legacy_encoding): New function.

* file-handle.q: Parse new formats.
(cmd_file_handle): Set up new formats.

* print.c (struct print_trns): New member `encoding'.
(internal_cmd_print): Set encoding.
(print_trns_proc): Recode output data if necessary.
(flush_records): Recode leader byte.

* data-in.c: Make formatted data parsing locale-independent.
(parse_number): Use c_strtod instead of strtod, to avoid
locale-specific behavior.
(parse_Z): Ditto.