Added a "dispose" method to PhaseLockedVocoder to clear the au wavetable (#40)

* Fixing a memory leak from not deallocating audio data pointer

* Moved the deallocation of theData to the end

* cleaned up unneeded deallocation in 164

* Added a "dispose" method to clear the au wavetable

* removed white space

* Corrected a default param value in ZitaReverb

The value range is 160.0...1000.0, but the default value was 1500.0
Nothing bad happened because of this, but now it is more correct, with a default value of 1000.0.

Author: maweibezahn

Sources/SoundpipeAudioKit/Effects/ZitaReverb.swift

@@ -114,7 +114,7 @@ public class ZitaReverb: Node {
         identifier: "EQ Frequency 2",
         name: "EQ Frequency 2",
         address: akGetParameterAddress("ZitaReverbParameterEqualizerFrequency2"),
-        defaultValue: 1500.0,
+        defaultValue: 1000.0,
         range: 160.0 ... 1000.0,
         unit: .hertz
     )

Sources/SoundpipeAudioKit/Generators/PhaseLockedVocoder.swift

@@ -79,7 +79,12 @@ public class PhaseLockedVocoder: Node {
         self.amplitude = amplitude
         self.pitchRatio = pitchRatio
     }
-
+    
+    /// Call this function after you are done with the node, to reset the au wavetable to prevent memory leaks
+    public func dispose() {
+        au.setWaveTable([0.0])
+    }
+    
     internal func loadFile(_ avAudioFile: AVAudioFile) {
         Exit: do {
             var err: OSStatus = noErr