Update to 4.39:
- Automatic creation of subdirectories of auxdir
- Add error diagnostics to if_source
- Allow print_type = 'auto'
- Fix use of directories with names containing perl glob characters
- Ensure that subdirectories are created properly
- In output of dependencies, include pathname of target file(s) in the rule.
- In -pvc mode, writing of deps file is per make not per overall run.