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/mouse/juce_TooltipClient.h

@@ -0,0 +1,89 @@
+/*
+  ==============================================================================
+
+   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
+{
+
+//==============================================================================
+/**
+    Components that want to use pop-up tooltips should implement this interface.
+
+    A TooltipWindow will wait for the mouse to hover over a component that
+    implements the TooltipClient interface, and when it finds one, it will display
+    the tooltip returned by its getTooltip() method.
+
+    @see TooltipWindow, SettableTooltipClient
+
+    @tags{GUI}
+*/
+class JUCE_API  TooltipClient
+{
+public:
+    /** Destructor. */
+    virtual ~TooltipClient()  {}
+
+    /** Returns the string that this object wants to show as its tooltip. */
+    virtual String getTooltip() = 0;
+};
+
+
+//==============================================================================
+/**
+    An implementation of TooltipClient that stores the tooltip string and a method
+    for changing it.
+
+    This makes it easy to add a tooltip to a custom component, by simply adding this
+    as a base class and calling setTooltip().
+
+    Many of the JUCE widgets already use this as a base class to implement their
+    tooltips.
+
+    @see TooltipClient, TooltipWindow
+
+    @tags{GUI}
+*/
+class JUCE_API  SettableTooltipClient   : public TooltipClient
+{
+public:
+    //==============================================================================
+    /** Destructor. */
+    ~SettableTooltipClient() {}
+
+    //==============================================================================
+    /** Assigns a new tooltip to this object. */
+    virtual void setTooltip (const String& newTooltip)              { tooltipString = newTooltip; }
+
+    /** Returns the tooltip assigned to this object. */
+    String getTooltip() override                                    { return tooltipString; }
+
+protected:
+    SettableTooltipClient() {}
+
+private:
+    String tooltipString;
+};
+
+} // namespace juce