Documenting mouse accessibility and onscreen keyboard options.

Normalizing those options ('-' instead of '_' in their names, like other opts.)

docs/html/OPTIONS.html

@@ -23,7 +23,7 @@ New Breed Software</p>
 <a href="http://www.tuxpaint.org/">http://www.tuxpaint.org/</a></p>
 
 
-<p>January 12, 2011</p>
+<p>April 13, 2011</p>
 
 
 </center>
@@ -460,6 +460,18 @@ New Breed Software</p>
     rather than left-to-right.</p>
   </dd>
 
+  <dt><code><b>mouse-accessibility=yes</b></code></dt>
+  <dd>
+    In this mode, instead of clicking, dragging and releasing
+    (e.g., to draw), you click, move, and click again to end the motion.
+  </dd>
+
+  <dt><code><b>onscreen-keyboard=yes</b></code></dt>
+  <dd>
+    Presents a clickable on-screen keyboard when using the <b>Text</b> and
+    <b>Label</b> tools.
+  </dd>
+
   <dt><code><b>stampsize=<i>SIZE</i></b></code></dt>
   <dd>
     <p>Use this option to force Tux&nbsp;Paint to set the starting size of
@@ -1182,6 +1194,8 @@ New Breed Software</p>
     --nostampcontrols<br>
     --nomagiccontrols<br>
     --nolabel<br>
+    --mouse-accessibility<br>
+    --onscreen-keyboard<br>
     --sysfonts<br>
     --alllocalefonts<br>
     --mirrorstamps<br>