CR: Allow empty lists in class EHR

Hi!

The current java code does not allow empty lists for contributions and
compositions when creating new EHR objects this is stricter than the
specification. The spec only states that the target of the attributes
pointing to the lists must not be null. My interpretation is that
empty lists should be allowed and that empty lists are useful when
creating a new blank EHR.

The patch below describes my little change proposal. Do you want me to
submit it to the TRUNK version in SVN?

Best regards,
Erik Sundvall
http://www.imt.liu.se/~erisu/

Index: E:/workspace/ref_impl_java_TRUNK/openehr-rm-domain/src/main/java/org/openehr/rm/ehr/EHR.java

I will do the change together with renaming of attribute allCompositions.
/Rong