Fix to Lazy loading problem when loading full data by name. Might
introduce memory leak if reference to DataHolder is kept because by
using the LoaderFactory to load the full data, the value is cached in
the DataHolder.
Merge branch 'master' of ssh://dascgitolite@dasc-git.diamond.ac.uk/scisoft/scisoft-core.git
Avoided NPE on clone which happens with tiffs.