header-vars: new variable $(am__running_with_option) This is a preparatory refactoring, needed by later patches. No semantic change is intended. * lib/am/header-vars.am (am__running_with_option): New, contains shell code that determines whether the current make instance is running with a given one-letter option (e.g., -k, -n) that takes no argument. Actually, the only supported option at the moment is '-n' (support for '-k' will be added soon). (am__make_dryrun): Rewrite as a thin wrapper around '$(am__make_running_with_option)'. Signed-off-by: Stefano Lattarini <stefano.lattarini@gmail.com>