Add "Double nodes tolerance" preference
<b>Quality Control</b> diagrams at the necessary level of precision.</li>
<li><b>Number of digits after point</b> - defines precision for <b>Quality Controls</b>. By default, numbers in <b>Quality Control</b>
diagrams are presented as integers.</li>
+<li><b>Double nodes tolerance</b> defines maximal distance between two
+mesh nodes at which they are considered coincident by <b>Double nodes</b>
+quality control.
</ul>
<li><b>Display mode</b> - allows to set Wireframe, Shading, Nodes or Shrink
presentation mode as default.</li>