[[Imported from SVN: r7365]]

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]]

[[Imported from SVN: r7354]]

[[Imported from SVN: r7353]]

[[Imported from SVN: r7352]]

[[Imported from SVN: r7351]]

[[Imported from SVN: r7350]]

[[Imported from SVN: r7348]]

[[Imported from SVN: r7346]]

[[Imported from SVN: r7345]]

[[Imported from SVN: r7344]]

[[Imported from SVN: r7342]]

[[Imported from SVN: r7341]]

[[Imported from SVN: r7338]]

[[Imported from SVN: r7314]]

[[Imported from SVN: r7313]]

[[Imported from SVN: r7312]]

[[Imported from SVN: r7311]]

[[Imported from SVN: r7286]]

instead of a singular value decomposition.  This makes computing
a Hesse matrix roughly 20% faster.

[[Imported from SVN: r7232]]

using a finite-difference approximation only for the derivative
of the gfe gradients wrt coefficients.

[[Imported from SVN: r7230]]

[[Imported from SVN: r7229]]

[[Imported from SVN: r7228]]

[[Imported from SVN: r7227]]

[[Imported from SVN: r7225]]

[[Imported from SVN: r7206]]

[[Imported from SVN: r7205]]

[[Imported from SVN: r7196]]

[[Imported from SVN: r7195]]

Also: fix more bugs in the implementation of the derivative of gfe
function gradients wrt the coefficients.  This appears to work now,
but inexact evaluations remain an issue.

[[Imported from SVN: r7180]]

[[Imported from SVN: r7179]]

[[Imported from SVN: r7177]]

[[Imported from SVN: r7176]]

rename method assembleHessian of AverageDistanceAssembler to assembleEmbeddedHessian, to make clearer what it does

[[Imported from SVN: r7175]]

[[Imported from SVN: r7174]]

method to compute the actual Hesse matrix.  For some strange reason this slows down convergence, rather than speeding it up.  to be investigated

[[Imported from SVN: r7173]]

[[Imported from SVN: r7172]]

[[Imported from SVN: r7135]]

[[Imported from SVN: r7134]]

[[Imported from SVN: r7133]]