Fixes to the documentation. Added missing --revoked logic for the list command.

ca.go

@@ -460,9 +460,19 @@ func issueSingleCertificate(def CertificateDefinition, i int, n int) (bool, erro
 		return false, fmt.Errorf("certificate name must be specified and contain only letters, numbers, dash, or underscore")
 	}
 
-	// Check if the certificate is in database, fail if it is.
+	// Check if the certificate is in database, skip if it already exists and is valid.
 	if caState.FindByName(def.Name, false) != nil {
-		return false, fmt.Errorf("certificate %s already exists and is valid", def.Name)
+		if !dryRun {
+			fmt.Printf("skipped (already exists).\n")
+		} else {
+			msg := fmt.Sprintf("Certificate '%s' already exists and is valid (would skip).", def.Name)
+			if n > 1 {
+				fmt.Printf("[%d/%d] %s\n", i+1, n, msg)
+			} else {
+				fmt.Printf("%s\n", msg)
+			}
+		}
+		return false, nil
 	}
 
 	// Initialize Subject if not specified