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_audio_plugin_client/utility/juce_WindowsHooks.h

@@ -0,0 +1,111 @@
+/*
+  ==============================================================================
+
+   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.
+
+  ==============================================================================
+*/
+
+#if JUCE_WINDOWS
+
+namespace juce
+{
+
+// This function is in juce_win32_Windowing.cpp
+extern bool offerKeyMessageToJUCEWindow (MSG&);
+
+namespace
+{
+    static HHOOK mouseWheelHook = 0, keyboardHook = 0;
+    static int numHookUsers = 0;
+
+    struct WindowsHooks
+    {
+        WindowsHooks()
+        {
+            if (numHookUsers++ == 0)
+            {
+                mouseWheelHook = SetWindowsHookEx (WH_MOUSE, mouseWheelHookCallback,
+                                                   (HINSTANCE) juce::Process::getCurrentModuleInstanceHandle(),
+                                                   GetCurrentThreadId());
+
+                keyboardHook = SetWindowsHookEx (WH_GETMESSAGE, keyboardHookCallback,
+                                                 (HINSTANCE) juce::Process::getCurrentModuleInstanceHandle(),
+                                                 GetCurrentThreadId());
+            }
+        }
+
+        ~WindowsHooks()
+        {
+            if (--numHookUsers == 0)
+            {
+                if (mouseWheelHook != 0)
+                {
+                    UnhookWindowsHookEx (mouseWheelHook);
+                    mouseWheelHook = 0;
+                }
+
+                if (keyboardHook != 0)
+                {
+                    UnhookWindowsHookEx (keyboardHook);
+                    keyboardHook = 0;
+                }
+            }
+        }
+
+        static LRESULT CALLBACK mouseWheelHookCallback (int nCode, WPARAM wParam, LPARAM lParam)
+        {
+            if (nCode >= 0 && wParam == WM_MOUSEWHEEL)
+            {
+                // using a local copy of this struct to support old mingw libraries
+                struct MOUSEHOOKSTRUCTEX_  : public MOUSEHOOKSTRUCT  { DWORD mouseData; };
+
+                auto& hs = *(MOUSEHOOKSTRUCTEX_*) lParam;
+
+                if (auto* comp = Desktop::getInstance().findComponentAt ({ hs.pt.x, hs.pt.y }))
+                    if (comp->getWindowHandle() != 0)
+                        return PostMessage ((HWND) comp->getWindowHandle(), WM_MOUSEWHEEL,
+                                            hs.mouseData & 0xffff0000, (hs.pt.x & 0xffff) | (hs.pt.y << 16));
+            }
+
+            return CallNextHookEx (mouseWheelHook, nCode, wParam, lParam);
+        }
+
+        static LRESULT CALLBACK keyboardHookCallback (int nCode, WPARAM wParam, LPARAM lParam)
+        {
+            MSG& msg = *(MSG*) lParam;
+
+            if (nCode == HC_ACTION && wParam == PM_REMOVE
+                 && offerKeyMessageToJUCEWindow (msg))
+            {
+                zerostruct (msg);
+                msg.message = WM_USER;
+                return 1;
+            }
+
+            return CallNextHookEx (keyboardHook, nCode, wParam, lParam);
+        }
+    };
+}
+
+} // juce namespace
+
+#endif