Log Message:
Update to 1.23.0. From the changelog:

- "redo-ifchange"’s "-f" option forces each target rebuilding.
  Comparing to "redo", it will parallelize the process.
- Inode’s number is also stored as dependency information, just to
  prevent possible "ctime" collision of two files.
- Performance optimization: do not use target’s temporary output file
  at all, if its hash equals to already existing target’s one.  Just
  touch existing target file instead.