Log Message:
Update sptk to 3.5.
PR 46047 by ISHIHARA Takanori.

Version 3.5:
 * add 'dtw' command.
 * add 'mfcc' command.
 * add 'mgc2mgclsp' and 'mgclsp2mgc' command.
 * add two pitch extraction algorithm, 'RAPT' and 'SWIPE' to 'pitch' command.
 * add -R and -M option to 'delta' command, to skip the magic number during the
   calculation.
 * unify data type for sampling frequency into float in kHz.
 * fix options of 'psgr' and 'grlogsp' command to draw more large graph.
 * fix 'wav2raw' to deal with IEEE float format.
 * bug fixes.