Merge branch 'make-clean' into pu

* branch make-clean:
  Makefile: add "clean" target

Add a "clean" target to the makefile.
Merge branch 'version' into pu

* branch version:
  Add --version option

Support for "--version" option.
Merge branch 'skip-option' into pu

* branch skip-option:
  WIP
  Add --skip option

Needs more work to be able to handle "branch not found".
Merge branch 'manpage-on-site' into pu

* branch manpage-on-site:
  WIP

WIP to improve the web site