fix macOS build (following Projucer changes made in Windows, which removed /Applications/JUCE/modules from its headers). move JUCE headers under source control, so that Windows and macOS can both build against same version of JUCE. remove AUv3 target (I think it's an iOS thing, so it will never work with this macOS fluidsynth dylib).

modules/juce_core/native/java/AndroidWebView.java

@@ -0,0 +1,69 @@
+$$WebViewNativeApi23    private native void webViewReceivedError (long host, WebView view, WebResourceRequest request, WebResourceError error);WebViewNativeApi23$$
+$$WebViewNativeApi21    private native void webViewReceivedHttpError (long host, WebView view, WebResourceRequest request, WebResourceResponse errorResponse);WebViewNativeApi21$$
+
+$$WebViewApi1_10
+        @Override
+        public void onPageStarted (WebView view, String url, Bitmap favicon)
+        {
+            if (host != 0)
+                webViewPageLoadStarted (host, view, url);
+        }
+WebViewApi1_10$$
+
+$$WebViewApi11_20
+        @Override
+        public WebResourceResponse shouldInterceptRequest (WebView view, String url)
+        {
+            synchronized (hostLock)
+            {
+                if (host != 0)
+                {
+                    boolean shouldLoad = webViewPageLoadStarted (host, view, url);
+
+                    if (shouldLoad)
+                        return null;
+                }
+            }
+
+            return new WebResourceResponse ("text/html", null, null);
+        }
+WebViewApi11_20$$
+
+$$WebViewApi21
+        @Override
+        public WebResourceResponse shouldInterceptRequest (WebView view, WebResourceRequest request)
+        {
+            synchronized (hostLock)
+            {
+                if (host != 0)
+                {
+                    boolean shouldLoad = webViewPageLoadStarted (host, view, request.getUrl().toString());
+
+                    if (shouldLoad)
+                        return null;
+                }
+            }
+
+            return new WebResourceResponse ("text/html", null, null);
+        }
+WebViewApi21$$
+
+$$WebViewApi23
+        @Override
+        public void onReceivedError (WebView view, WebResourceRequest request, WebResourceError error)
+        {
+            if (host == 0)
+                return;
+
+            webViewReceivedError (host, view, request, error);
+        }
+
+        @Override
+        public void onReceivedHttpError (WebView view, WebResourceRequest request, WebResourceResponse errorResponse)
+        {
+            if (host == 0)
+                return;
+
+            webViewReceivedHttpError (host, view, request, errorResponse);
+        }
+WebViewApi23$$