Split separate sources for field, element shape and FE_element_field_values (now FE_element_field_evaluation) from finite_element.cpp.
FE_element_field_evaluation now evaluates derivatives by taking derivatives of basis functions, not manipulating parameters to use with same basis as plain field.
Make several optimisations to field cache, and field location.
Split separate sources for field, element shape and FE_element_field_values (now FE_element_field_evaluation) from finite_element.cpp. FE_element_field_evaluation now evaluates derivatives by taking derivatives of basis functions, not manipulating parameters to use with same basis as plain field. Make several optimisations to field cache, and field location.