Tabulation of higher order derivatives broken for custom integrals

[Anders Logg (Chalmers)]

The copying of values from evaluate_basis_derivatives_all in code generated for custom_integral is incorrect. FE_Dij arrays etc don't double-count derivatives which are the same (xy same as yx) whereas this happens in values emanating from evaluate_basis_derivatives_all.

[Anders Logg (Chalmers)]

Fix issue #57: Tabulation of higher order derivatives broken for custom integrals

→ <<cset 3e1ea79265c6>>