cherrypick from hc-mr2, updated adk installation instructions Change-Id:...

      <p>On Mac:</p>

      <ol type="a">

        <li>Right-click on the Arduino application in Finder and select <strong>Show Package

        Contents</strong>.</li>

        <li>Create, if it does not already exist, an <code>Arduino</code>

        directory inside your user account's <code>Documents</code> directory, and within

        that, a <code>libraries</code> directory.</li>

        <li>Copy the <code>firmware/arduino_libs/AndroidAccessory</code> and

        <code>firmware/arduino_libs/USB_Host_Shield</code> directories (the complete directories,

        not just the files within) to the <code>Contents/Resources/Java/libraries</code> directory

        inside the Arduino application.</li>

        <code>firmware/arduino_libs/USB_Host_Shield</code> directories (the

        complete directories, not just the files within) to your

        <code>Documents/Arduino/libraries/</code> directory.</li>

        <li>Create a <code>CapSense</code> directory in the

        <code>Contents/Resources/Java/libraries</code> directory.</li>

        <li>Create a <code>CapSense</code> directory in your

        <code>Documents/Arduino/libraries/</code> directory.</li>

        <li>Copy <code>CapSense.cpp</code> and <code>CapSense.h</code> from the unzipped CapSense

        download to the <code>CapSense</code> directory.</li>