Remove representation link to ITEM; define interfaces only.
Move Hierarchical representation package to EHR_Extract Package. Use
classes such as X_LIST_S which inherit from LIST_S and add a
representation of type ITEM.
Rationale: removes need for EHR apps to use a particular
DK: This sounds quite radical! Unless I've misunderstood this is
likely to have quite an impact on how the openEHR model is understood
and cross-mapped to standards such as CEN and HL7. Suggest this should
not be rushed through now for version 0.9.
implementation - they just need to obey interfaces of data structures.
Hierarchical representation reserved for EHR extracts.
Note that hierarchical form is actually good for XML, but not for