Merge branch 'maint' * maint: options: try to report as much errors as possible warns: don't tell AM_PROG_MKDIR_P is going to be removed refactor: fix few "inverted boolean" usages options: better name for an internal function options: more consistency in use of return statuses to report errors options: tiny simplification in dealing with erroneous opts options: consistently use return statuses to report errors options: re-enable some sanity checks THANKS: update Eric Blake's e-mail address NEWS: typofix Signed-off-by: Stefano Lattarini <stefano.lattarini@gmail.com>