Ignore .adlf files
Update EHR Extract template to have correct differential syntax
Add some flattening archetype examples.
Enable .adlf files for regression testing of flattening
Update test archetypes to ADL 1.0.0; add .adlf flat form files for regression testing.
Fix code numbers in flattening clone archetype.
Corrections to slot / filler archetypes.
Update some generated CKM archetypes with new ADL 2 version.
Remainder of CKM updates to ADL 2.
Final ADL2 cosmetic changes
Correct errors in template example archetypes
Update some test archetypes to reflect the errors currently generated by them.
Add test archetype for governance meta-data
Move copyright in accordance with ADL 2
Upgrade location of copyright in description section to ADL 2 location.
Merge pull request #2 from openEHR/master

Updates from master