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_core/threads/juce_HighResolutionTimer.h

@@ -0,0 +1,104 @@
+/*
+  ==============================================================================
+
+   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.
+
+   The code included in this file is provided under the terms of the ISC license
+   http://www.isc.org/downloads/software-support-policy/isc-license. Permission
+   To use, copy, modify, and/or distribute this software for any purpose with or
+   without fee is hereby granted provided that the above copyright notice and
+   this permission notice appear in all copies.
+
+   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
+{
+
+/**
+    A high-resolution periodic timer.
+
+    This provides accurately-timed regular callbacks. Unlike the normal Timer
+    class, this one uses a dedicated thread, not the message thread, so is
+    far more stable and precise.
+
+    You should only use this class in situations where you really need accuracy,
+    because unlike the normal Timer class, which is very lightweight and cheap
+    to start/stop, the HighResolutionTimer will use far more resources, and
+    starting/stopping it may involve launching and killing threads.
+
+    @see Timer
+
+    @tags{Core}
+*/
+class JUCE_API  HighResolutionTimer
+{
+protected:
+    /** Creates a HighResolutionTimer.
+        When created, the timer is stopped, so use startTimer() to get it going.
+    */
+    HighResolutionTimer();
+
+public:
+    /** Destructor. */
+    virtual ~HighResolutionTimer();
+
+    //==============================================================================
+    /** The user-defined callback routine that actually gets called periodically.
+
+        This will be called on a dedicated timer thread, so make sure your
+        implementation is thread-safe!
+
+        It's perfectly ok to call startTimer() or stopTimer() from within this
+        callback to change the subsequent intervals.
+    */
+    virtual void hiResTimerCallback() = 0;
+
+    //==============================================================================
+    /** Starts the timer and sets the length of interval required.
+
+        If the timer is already started, this will reset its counter, so the
+        time between calling this method and the next timer callback will not be
+        less than the interval length passed in.
+
+        @param  intervalInMilliseconds  the interval to use (any values less than 1 will be
+                                        rounded up to 1)
+    */
+    void startTimer (int intervalInMilliseconds);
+
+    /** Stops the timer.
+
+        This method may block while it waits for pending callbacks to complete. Once it
+        returns, no more callbacks will be made. If it is called from the timer's own thread,
+        it will cancel the timer after the current callback returns.
+    */
+    void stopTimer();
+
+    /** Checks if the timer has been started.
+        @returns true if the timer is running.
+    */
+    bool isTimerRunning() const noexcept;
+
+    /** Returns the timer's interval.
+        @returns the timer's interval in milliseconds if it's running, or 0 if it's not.
+    */
+    int getTimerInterval() const noexcept;
+
+private:
+    struct Pimpl;
+    friend struct Pimpl;
+    friend struct ContainerDeletePolicy<Pimpl>;
+    std::unique_ptr<Pimpl> pimpl;
+
+    JUCE_DECLARE_NON_COPYABLE_WITH_LEAK_DETECTOR (HighResolutionTimer)
+};
+
+} // namespace juce