Merge branch 'development_0.9.3/2.2.1' of gitlab.surrey.ac.uk:ri0005/binary_c-python into development_0.9.3/2.2.1

add check for empty dict (or None) in recursive_change_key_to_float, as for some reason this was failing. In this case, return an empty dict.

(oops)

couple of other typo fixes