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/components/juce_CachedComponentImage.h

@@ -0,0 +1,73 @@
+/*
+  ==============================================================================
+
+   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
+{
+
+//==============================================================================
+/**
+    Base class used internally for structures that can store cached images of
+    component state.
+
+    Most people are unlikely to ever need to know about this class - it's really
+    only for power-users!
+
+    @see Component::setCachedComponentImage
+
+    @tags{GUI}
+*/
+class JUCE_API  CachedComponentImage
+{
+public:
+    CachedComponentImage() noexcept {}
+    virtual ~CachedComponentImage() {}
+
+    //==============================================================================
+    /** Called as part of the parent component's paint method, this must draw
+        the given component into the target graphics context, using the cached
+        version where possible.
+    */
+    virtual void paint (Graphics&) = 0;
+
+    /** Invalidates all cached image data.
+        @returns true if the peer should also be repainted, or false if this object
+                 handles all repaint work internally.
+    */
+    virtual bool invalidateAll() = 0;
+
+    /** Invalidates a section of the cached image data.
+        @returns true if the peer should also be repainted, or false if this object
+                 handles all repaint work internally.
+    */
+    virtual bool invalidate (const Rectangle<int>& area) = 0;
+
+    /** Called to indicate that the component is no longer active, so
+        any cached data should be released if possible.
+    */
+    virtual void releaseResources() = 0;
+};
+
+} // namespace juce