Merge from vendor branch TNF:

Merge from vendor branch TNF:

NIH Invented Here :-)
This is a package manager for pkgsrc.

Available commands:
   nih help            - Display help message
   nih refresh         - Download pkg_summary and SHA512 files
   nih install         - Install or update packages
   nih uninstall       - Uninstall packages
   nih verify          - Verify packages integrity
   nih status          - Show status of installed packages
   nih info            - Show information about packages
   nih meta            - Output available or installed meta packages
   nih search          - Powerful search in packages
   nih leaf            - Output or remove autoinstalled leaf packages
   nih list            - List packages
   nih mark            - Mark packages
   nih deps            - Show dependencies
   nih clean-cache     - Clean-up cache directory with binaries