Solve the minimization problems for the evaluation of gfe functions really...

Solve the minimization problems for the evaluation of gfe functions really down to machine precision.  This appears to make the overall algorithm much more stable

[[Imported from SVN: r7355]]

dune/gfe/localgeodesicfefunction.hh

@@ -191,11 +191,11 @@ evaluate(const Dune::FieldVector<ctype, dim>& local) const
 
     solver.setup(&assembler,
                  coefficients_[0],   // initial iterate
-                 1e-8,    // tolerance
-                 20,      // maxTrustRegionSteps
+                 1e-14,    // tolerance
+                 100,      // maxTrustRegionSteps
                  2,       // initial trust region radius
-                 20,      // inner iterations
-                 1e-8     // inner tolerance
+                 100,      // inner iterations
+                 1e-14     // inner tolerance
                  );
 
     solver.solve();