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_product_unlocking/juce_product_unlocking.cpp

@@ -0,0 +1,69 @@
+/*
+  ==============================================================================
+
+   This file is part of the JUCE library.
+   Copyright (c) 2017 - ROLI Ltd.
+
+   JUCE is an open source library subject to commercial or open-source
+   licensing.
+
+   By using JUCE, you agree to the terms of both the JUCE 5 End-User License
+   Agreement and JUCE 5 Privacy Policy (both updated and effective as of the
+   27th April 2017).
+
+   End User License Agreement: www.juce.com/juce-5-licence
+   Privacy Policy: www.juce.com/juce-5-privacy-policy
+
+   Or: You may also use this code under the terms of the GPL v3 (see
+   www.gnu.org/licenses).
+
+   JUCE IS PROVIDED "AS IS" WITHOUT ANY WARRANTY, AND ALL WARRANTIES, WHETHER
+   EXPRESSED OR IMPLIED, INCLUDING MERCHANTABILITY AND FITNESS FOR PURPOSE, ARE
+   DISCLAIMED.
+
+  ==============================================================================
+*/
+
+#ifdef JUCE_PRODUCT_UNLOCKING_H_INCLUDED
+ /* When you add this cpp file to your project, you mustn't include it in a file where you've
+    already included any other headers - just put it inside a file on its own, possibly with your config
+    flags preceding it, but don't include anything else. That also includes avoiding any automatic prefix
+    header files that the compiler may be using.
+ */
+ #error "Incorrect use of JUCE cpp file"
+#endif
+
+#define JUCE_CORE_INCLUDE_JNI_HELPERS    1
+#define JUCE_CORE_INCLUDE_OBJC_HELPERS   1
+#define JUCE_CORE_INCLUDE_NATIVE_HEADERS 1
+
+// Set this flag to 1 to use test servers on iOS
+#ifndef JUCE_IN_APP_PURCHASES_USE_SANDBOX_ENVIRONMENT
+    #define JUCE_IN_APP_PURCHASES_USE_SANDBOX_ENVIRONMENT 0
+#endif
+
+#include "juce_product_unlocking.h"
+
+#if JUCE_IOS || JUCE_MAC
+ #import <StoreKit/StoreKit.h>
+#endif
+
+#if JUCE_IN_APP_PURCHASES
+ #if JUCE_ANDROID
+  #include "native/juce_android_InAppPurchases.cpp"
+ #elif JUCE_IOS || JUCE_MAC
+  #include "native/juce_ios_InAppPurchases.cpp"
+ #endif
+
+ #include "in_app_purchases/juce_InAppPurchases.cpp"
+#endif
+
+#include "marketplace/juce_OnlineUnlockStatus.cpp"
+
+#if JUCE_MODULE_AVAILABLE_juce_data_structures
+ #include "marketplace/juce_TracktionMarketplaceStatus.cpp"
+#endif
+
+#if JUCE_MODULE_AVAILABLE_juce_gui_extra
+ #include "marketplace/juce_OnlineUnlockForm.cpp"
+#endif