Fix issue 10.

interpolate_vertex_values for elements where reference and physical value size is different.
The fix will not extend to mixed elements, e.g. RT*DG0 on a manifold will likely fail.
Instead of failing, generate exception throw statement in interpolate_vertex_values.
Update reference data pointer to 54b142fc35907f9690bd814212e7cd5a19e4231a.
Update reference data pointer to ba6158f85405b65fe178200629c2bc35c501855f.
Merge branch 'martinal/fix-issue-10'

Conflicts:
	test/regression/ffc-reference-data-id