WIP: Shape controls -- center vs corner

Adding control buttons to the Shapes tool, allowing for shapes
to be drawn from the center (as before) or from a corner
(more like other paint packages).  The controls do nothing
at this time, but are visible and can be clicked.  This is a
work in progress.

The controls may be removed using a configuration option.

docs/CHANGES.txt

@@ -27,6 +27,13 @@ $Id$
       * The "--exportdir" option can be used to override the default
         location (but a "TuxPaint" subdir. will NOT be placed there).
 
+    * Shape controls: -- WORK IN PROGRESS
+      * Draw shapes from the center (as in previous versions of Tux Paint)
+        or from a corner (similar to the default mode of most other
+        graphics tools).
+      * The controls to modify the drawing behavior can be removed,
+        for simplification of Tux Paint's interface (for younger users).
+
   * Ports & Building
     ----------------
     * Corrections for Haiku not opening saved files.

docs/en/OPTIONS.txt

@@ -6,7 +6,7 @@ Options Documentation
         Copyright (c) 2002-2020 by various contributors; see AUTHORS.txt
                             http://www.tuxpaint.org/
 
-                                 July 27, 2020
+                                August 14, 2020
 
      ----------------------------------------------------------------------
 
@@ -358,6 +358,12 @@ Windows Users
              controls, and only provides the default functionality (usually
              paint-mode).
 
+     noshapecontrols=yes
+             Disable the control buttons shown when using the Shapes tool
+             that allow changing how shapes are drawn — centered around the
+             initial mouse click, or with a corner at the initial mouse
+             click.
+
      nolabel=yes
              Disables the Label tool: the tool that allows text entry which
              can be edited later.
@@ -1018,6 +1024,7 @@ Windows Users
        --nostamps
        --nostampcontrols
        --nomagiccontrols
+       --noshapecontrols
        --nolabel
        --newcolorslast
        --mouse-accessibility
@@ -1091,6 +1098,7 @@ Windows Users
        --stamps
        --stampcontrols
        --magiccontrols
+       --shapecontrols
        --label
        --newcolorsfirst
        --nosysfonts

docs/en/html/OPTIONS.html

@@ -32,7 +32,7 @@
       </p>
 
       <p>
-        July 27, 2020
+        August 14, 2020
       </p>
     </center>
 
@@ -742,6 +742,17 @@
           default functionality (usually paint-mode).
         </dd>
 
+        <dt>
+          <code><b>noshapecontrols=yes</b></code>
+        </dt>
+
+        <dd>
+          Disable the control buttons shown when using the <b>Shapes</b>
+          tool that allow changing how shapes are drawn &mdash;
+          centered around the initial mouse click, or with a corner
+          at the initial mouse click.
+        </dd>
+
         <dt>
           <code><b>nolabel=yes</b></code>
         </dt>
@@ -3090,6 +3101,7 @@
             --nostamps<br>
             --nostampcontrols<br>
             --nomagiccontrols<br>
+            --noshapecontrols<br>
             --nolabel<br>
             --newcolorslast<br>
             --mouse-accessibility<br>
@@ -3170,6 +3182,7 @@
             --stamps<br>
             --stampcontrols<br>
             --magiccontrols<br>
+            --shapecontrols<br>
             --label<br>
             --newcolorsfirst<br>
             --nosysfonts<br>