inefficient data types

[mikebosse]

The base coefficient class already declares the values as a dynamic eigen vector, so when implementing derived classes we can't really take advantage of efficient statically sized vectors.

Is there a better way to design the interfaces, perhaps to use more templates, so that we can take advantage of efficient Block Auto Differentiation routines, and not have so much superfluous allocation, deallocation and copying of data?

[gawela]

@mikebosse I think we go much closer to this goal with the latest developments - do you think we can close this issue?