Log Message:
Update sptk to 3.4.1.
In addition to PR#45024 by ISIHARA Takanori,
* also update refrence manual and examples PDF document files.
* exactly depend on csh, some installed scripts are csh script.

Version 3.4.1:
 * add 'idct' command.
 * remove all input/output data type except float from 'frame', 'snr', 'us16',
   and 'uscd' command.
 * add input/output data type to many commands.
 * show number of byte for all input/output data type in 'x2x' command.
 * rename 'pcap' command to 'pcas' command.
 * add new constant (octave and cent) to 'sopr' command.
 * bug fixes.