fixed some minor typos in the docu.

doc/html/user-manual.html

@@ -616,7 +616,7 @@ in case a <span class="math">\(\chi^2\)</span> single-histogram fit is done, als
 <tr class="row-odd"><td>generExpo</td>
 <td>ge</td>
 <td><span class="math">\(\lambda (\mu \mathrm{s}^{-1}) \beta(1)\)</span></td>
-<td><span class="math">\(\exp\left[(-\lambda t)^\beta\right]\)</span></td>
+<td><span class="math">\(\exp\left[-(\lambda t)^\beta\right]\)</span></td>
 <td>&nbsp;</td>
 </tr>
 <tr class="row-even"><td>simpleGss</td>
@@ -2294,7 +2294,7 @@ In case this cannot be ensured, the parallelization can be disabled by <em>&#821
     </div>
     <div class="footer">
         &copy; Copyright 2019, Andreas Suter.
-      Last updated on Jul 24, 2019.
+      Last updated on Nov 11, 2019.
       Created using <a href="http://sphinx-doc.org/">Sphinx</a> 1.2.3.
     </div>
   </body>