Added iterators to AudioFormatManager.

modules/juce_audio_formats/format/juce_AudioFormatManager.h

@@ -80,6 +80,12 @@ public:
     /** Returns one of the registered file formats. */
     AudioFormat* getKnownFormat (int index) const;
 
+    /** Iterator access to the list of known formats. */
+    AudioFormat** begin() const noexcept            { return knownFormats.begin(); }
+
+    /** Iterator access to the list of known formats. */
+    AudioFormat** end() const noexcept              { return knownFormats.end(); }
+
     /** Looks for which of the known formats is listed as being for a given file
         extension.