addbib: raise error for bad option (#1046)

* As with other scripts in bin/, treat getopts() failure as a fatal error (show usage and exit)
* Don't suppress Getopt warnings, so the user sees feedback on which option was incorrect

Author: mknos

bin/addbib

@@ -262,11 +262,7 @@ sub process_options {
 	my $class = shift;
 
 	local @ARGV = @_;
-	{
-	local $SIG{__WARN__} = sub { 1 };
-	Getopt::Std::getopts( 'ap:');
-	}
-
+	Getopt::Std::getopts( 'ap:') or $class->usage();
 	return $ARGV[0];
 	}