widgets.

4. Made sure that in the "vista" and "xpnative" themes the indicators of
   the ttk::checkbutton and ttk::radiobutton widgets will be properly
   scaled, regardless of the Tk release being used (a long-standing bug
   in the implementation of these widgets was fixed in May 2020).

5. Made the demo-scripts fully scaling-aware.

6. Several further improvements in the demo scripts and documentation.

What was new in Scrollutil 1.5?
-------------------------------

1. On Windows and X11, Scrollutil now automatically creates mouse wheel

   widgets.

4. Made sure that in the "vista" and "xpnative" themes the indicators of
   the ttk::checkbutton and ttk::radiobutton widgets will be properly
   scaled, regardless of the Tk release being used (a long-standing bug
   in the implementation of these widgets was fixed in May 2020).

5. Made the demo-scripts scaling-aware.

6. Several further improvements in the demo scripts and documentation.

What was new in Scrollutil 1.5?
-------------------------------

1. On Windows and X11, Scrollutil now automatically creates mouse wheel

  <ul>
    <li>The variable <code>scrollutil::version</code> holds the current version
    number of the Scrollutil package.</li>

    <li>The variable <code>scrollutil::library</code> holds the location of the
    Scrollutil installation directory.</li>

    <li>The read-only variable <code>scrollutil::scalingpct</code> holds the
    scaling percentage corresponding to the display's DPI scaling level.&nbsp;

    Scrollutil adapts the default width of the Tk core scrollbars on X11 and
    that of the ttk::scrollbar widget for the built-in themes <code>alt</code>,
    <code>clam</code>, <code>classic</code>, and <code>default</code> to the
    value of this variable.&nbsp; The currently supported values are
    <code>100</code>, <code>125</code>, <code>150</code>, <code>175</code>, and
    <code>200</code>.&nbsp; You can use this variable, e.g., if you want to
    create images of different sizes, depending on the DPI scaling level.&nbsp;
    For example, if your application uses images of size 16 x 16 on an unscaled
    display and <code>scrollutil::scalingpct</code> has the value
    <code>150</code>, then the image size for this display should be 24 x
    24.</li>

    <li>The read-only variable <code>scrollutil::usingTile</code> has the value
    <code>0</code> in the package Scrollutil and the value <code>1</code> in
    Scrollutil_tile.</li>
  </ul>

  <p>The Scrollutil_tile package checks whether the required Tk and tile

  <ul>
    <li>The variable <code>scrollutil::version</code> holds the current version
    number of the Scrollutil package.</li>

    <li>The variable <code>scrollutil::library</code> holds the location of the
    Scrollutil installation directory.</li>

    <li>The read-only variable <code>scrollutil::scalingpct</code> is set at
    application start time to the scaling percentage corresponding to the
    display's DPI scaling level.&nbsp; Scrollutil adapts, among others, the
    default width of the Tk core scrollbars on X11 and that of the
    ttk::scrollbar widget for the built-in themes <code>alt</code>,
    <code>clam</code>, <code>classic</code>, and <code>default</code> to the
    value of this variable.&nbsp; The currently supported values are
    <code>100</code>, <code>125</code>, <code>150</code>, <code>175</code>, and
    <code>200</code>.&nbsp; You can use this variable, e.g., if you want to
    create images of different sizes, depending on the DPI scaling level.&nbsp;
    For example, if your application uses images of size 16 x 16 on an unscaled
    display and <code>scrollutil::scalingpct</code> has the value
    <code>150</code>, then the image size for this display should be
    24 x 24.</li>

    <li>The read-only variable <code>scrollutil::usingTile</code> has the value
    <code>0</code> in the package Scrollutil and the value <code>1</code> in
    Scrollutil_tile.</li>
  </ul>

  <p>The Scrollutil_tile package checks whether the required Tk and tile