Amazingly, this really does have a measurable effect on the overall computation
speed.  Assembly times for the global Hessian and gradient for the Cosserat shell
energy problem drop by about 5% (!)

[[Imported from SVN: r9837]]

[[Imported from SVN: r9813]]

This has two advantages:
- The two matrices use different number types (adouble vs. double),
  but the generic multiplication in dune/istl/matrix.hh doesn't support
  that.  Hence before this change I had to patch dune-istl.
- It avoids one extra copying operation

[[Imported from SVN: r9703]]

The new initial iterate is constructed by interpolating the values in Euclidean
space, and projecting back onto TargetSpace.  This has two advantages:
1) It's a better initial iterate, so we should converge faster than starting
   from coefficients_[0]
2) It makes it easier for ADOL-C to pick up correct second derivatives.
   Hence we are able to reduce the minimum number of iterations of the
   target space tr solver.

[[Imported from SVN: r9683]]

[[Imported from SVN: r9588]]

[[Imported from SVN: r9404]]

[[Imported from SVN: r9403]]

[[Imported from SVN: r9381]]

[[Imported from SVN: r9380]]

[[Imported from SVN: r9378]]

[[Imported from SVN: r9309]]

[[Imported from SVN: r9306]]

[[Imported from SVN: r9299]]

[[Imported from SVN: r9298]]

[[Imported from SVN: r9297]]

[[Imported from SVN: r8553]]

This change makes the localgeodesicfefunction test fail again.
So there must be a bug in the corresponding non-finite-difference
code.  Looking at simplex cases confirms me in this opinion.
But I don't find the bug...

[[Imported from SVN: r8463]]

[[Imported from SVN: r8462]]

[[Imported from SVN: r8376]]

To compute the derivative you need the function value (see my paper).
Therefore, it is computed as the first thing in the evaluateDerivative
method.  However, frequently, the assembler also needs the function value,
and also computes it.  Hence the function value is computed twice.
Since computing the function values takes quite a bit of time
this patch removes that redundancy, at the price of a slightly
more complicated API: if you happen to know the correct function
value when calling evaluateDerivative, you can now hand over the
value.  Then evaluateDerivative uses that value instead of recomputing it.

Short measurements have shown a speed increase between 25% and 45%.

[[Imported from SVN: r8362]]

[[Imported from SVN: r8182]]

target space classes.  In particular, the coordinate type
now has to be given explicitly.

[[Imported from SVN: r8149]]

[[Imported from SVN: r8059]]

[[Imported from SVN: r8051]]

[[Imported from SVN: r8045]]

add method to get the i'th base coefficient of a localGfeFunction and implement this method for the RigidBodyMotion template specialization

[[Imported from SVN: r8031]]

[[Imported from SVN: r8002]]

[[Imported from SVN: r7999]]

Compiles, but is not tested yet.

[[Imported from SVN: r7997]]

[[Imported from SVN: r7961]]

[[Imported from SVN: r7959]]

Add an operator() with three arguments to grant access
to the individual entries.

[[Imported from SVN: r7934]]

[[Imported from SVN: r7925]]

[[Imported from SVN: r7913]]

[[Imported from SVN: r7906]]

[[Imported from SVN: r7905]]

[[Imported from SVN: r7898]]

[[Imported from SVN: r7886]]

simplify the code by making the AverageDistanceAssembler accept the interpolation weights in a std::vector of FieldVectors

[[Imported from SVN: r7885]]

[[Imported from SVN: r7848]]