First stab at building a block sparsity.
Update mass_vector_ffc demo
Working block matrix version. Building one sparsity instead of four.
Created the sparse blocks into a list.
Code generation for mat and rhs, about to do the assembly.
VecNests, Solver included. First attempt at a mixed space is working.
Fixed RHS. Packed coefficients. Flattened Vec Maps. Switched loops.
Pass the right iteration space index to the kernel
Need to allow lists in Sparsity constructor type checks
Zero local tensor before passing to local assembly kernel
Block sparsity by components of the field
Add base.MultiDat and check for instance instead of _name attribute
Add zero and _dim to MultiDat
Give MultiDat and MultiMap an __iter__ iterating of the list of components
Refactor ParLoop argument checking
Correctly declare OpenMP vectors
For a mixed field the local tensor is always 1x1
Exchange halos for each dataset in a mixed Dat
Correctly identify row and column maps for mixed spaces
Add mass_mixed_ffc demo