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_gui_basics/misc/juce_DropShadower.h

@@ -0,0 +1,82 @@
+/*
+  ==============================================================================
+
+   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.
+
+  ==============================================================================
+*/
+
+namespace juce
+{
+
+//==============================================================================
+/**
+    Adds a drop-shadow to a component.
+
+    This object creates and manages a set of components which sit around a
+    component, creating a gaussian shadow around it. The components will track
+    the position of the component and if it's brought to the front they'll also
+    follow this.
+
+    For desktop windows you don't need to use this class directly - just
+    set the Component::windowHasDropShadow flag when calling
+    Component::addToDesktop(), and the system will create one of these if it's
+    needed (which it obviously isn't on the Mac, for example).
+
+    @tags{GUI}
+*/
+class JUCE_API  DropShadower  : private ComponentListener
+{
+public:
+    //==============================================================================
+    /** Creates a DropShadower. */
+    DropShadower (const DropShadow& shadowType);
+
+    /** Destructor. */
+    ~DropShadower();
+
+    /** Attaches the DropShadower to the component you want to shadow. */
+    void setOwner (Component* componentToFollow);
+
+
+private:
+    //==============================================================================
+    class ShadowWindow;
+
+    Component* owner;
+    OwnedArray<Component> shadowWindows;
+    DropShadow shadow;
+    bool reentrant;
+    WeakReference<Component> lastParentComp;
+
+    void componentMovedOrResized (Component&, bool, bool) override;
+    void componentBroughtToFront (Component&) override;
+    void componentChildrenChanged (Component&) override;
+    void componentParentHierarchyChanged (Component&) override;
+    void componentVisibilityChanged (Component&) override;
+
+    void updateParent();
+    void updateShadows();
+
+    JUCE_DECLARE_NON_COPYABLE_WITH_LEAK_DETECTOR (DropShadower)
+};
+
+} // namespace juce