Added CLI helper to print invalid options errors for commands.

cli/src/main/groovy/com/jdbernard/wdiwtlt/cli/CommandLineInterface.groovy

@@ -454,11 +454,7 @@ Configuration:
             modelClass = modelClasses[Matcher.lastMatcher[0][1]]
             return library.getWhere(modelClass, [playlistId: playQueue.id])
         case ~/untagged files/: return library.untaggedFiles
-        default:
+        default: invalidOptionsErr('select') } }
-            logger.debug("Invalid select options: $options")
-            err "Invalid options to the ${cmdStyle}select${normalStyle}" +
-                " command. Use ${cmdStyle}help select${normalStyle} to " +
-                "see a list of valid options." } }
 
     private Playlist processPlay(String options, List<Model> selection) {
 
@@ -1040,7 +1036,6 @@ Play and Controlling Media:
 
 Playlist and Queue Management:
 
-    scan
     enqueue selection
     enqueue <selection-criteria>
 
@@ -1063,6 +1058,9 @@ Playlist and Queue Management:
     clear selection
     clear playlist <id | name>
 
+Library Management:
+
+    scan
 """
 
             default:
@@ -1071,6 +1069,11 @@ Playlist and Queue Management:
                 Thread.sleep(250)
                 break } }
 
+    private String invalidOptionsErr(String commandName) {
+        err "Invalid options to the ${cmdStyle}${commandName}${normalStyle}" +
+            " command. Use ${cmdStyle}help ${commandName}${normalStyle} to " +
+            "see a list of valid options." }
+
     private void playing(def player) {
         try {
             def mediaFiles = library.getMediaFilesWhere(playlistId: playQueue.id)