That space is a product space, and its LocalGeodesicFEFunction can be
implemented much more efficiently than the generic method.

[[Imported from SVN: r7551]]

and barycentric coordinates.  This is easy because we know the
number of element corners at compile time (I currently don't
see support for non-simplex elements at all).  This saves 
time, but not much: about 1%.

[[Imported from SVN: r7550]]

[[Imported from SVN: r7548]]

[[Imported from SVN: r7547]]

[[Imported from SVN: r7412]]

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: r7346]]

[[Imported from SVN: r7345]]

[[Imported from SVN: r7344]]

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

[[Imported from SVN: r7232]]

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]]

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

[[Imported from SVN: r7175]]

[[Imported from SVN: r7133]]

add a method with an fd approximation of the derivative of the function gradient.  only for testing purposes

[[Imported from SVN: r7130]]

[[Imported from SVN: r7128]]

[[Imported from SVN: r7127]]

[[Imported from SVN: r7126]]

[[Imported from SVN: r7125]]

transpose one gradient matrix.  This makes the code run, but it still doesn't work even for RealTuple<1>

[[Imported from SVN: r6547]]

[[Imported from SVN: r6546]]

[[Imported from SVN: r6545]]

[[Imported from SVN: r6544]]

übersetzt jetzt und stürzt nicht ab.  Es kommt allerdings noch Unfug raus.

[[Imported from SVN: r6451]]

[[Imported from SVN: r6301]]

[[Imported from SVN: r6298]]

[[Imported from SVN: r6297]]

[[Imported from SVN: r6215]]

That makes the code more readable, which is more important to me than
speed.  The stuff is difficult enough as it is.

[[Imported from SVN: r6214]]

[[Imported from SVN: r6213]]

factor out the computation of the linear part of the reference-simplex-to-standard-simplex computation

[[Imported from SVN: r6212]]

[[Imported from SVN: r6211]]

[[Imported from SVN: r5938]]

[[Imported from SVN: r5931]]

[[Imported from SVN: r5804]]

[[Imported from SVN: r5716]]

[[Imported from SVN: r5697]]

[[Imported from SVN: r5695]]

[[Imported from SVN: r5600]]