Automatic choice of representation needs to consider geometry degree

[Jan Blechta]

Quadrature and tensor do not generate accurate code for higher-order geometries. Uflacs and tsfc do. Higher-order geometry should cause:

1. Automatic choice will pick uflacs whenever possible
2. Invocation of quadrature/tensor will raise warning/error.

[Jan Blechta]

Both tasks implemented in pull request #45.

[Jan Blechta]

Fix in master since c0b1920.