Updates to Users Guide.

Double-click on waterfall sets Tol to a reduced (mode-dependent) value.
Tol is saved/restored on program restart.
Added digital gain slider for setting input level.
Garbage decode "15P6715P67WCV" is rejected.
Arrays ss and c0 are copied and saved when newdat=1.  Further processing is
done on the copies.


git-svn-id: svn+ssh://svn.code.sf.net/p/wsjt/wsjt/branches/wsjtx@2712 ab8295b8-cf94-4d9e-aec4-7959e3be5d79

plotter.cpp

@@ -382,6 +382,11 @@ void CPlotter::setTol(int n)                                 //setTol()
   DrawOverlay();
 }
 
+int CPlotter::Tol()                                         //Tol()
+{
+  return m_tol;
+}
+
 void CPlotter::setBinsPerPixel(int n)                       // set nbpp
 {
   m_binsPerPixel = n;