Initial work; not sure it's an optimal solution
Merge branch 'master' into incrementals
Only update book instance_update_date when absolutely necessary
Merge branch 'master' into incrementals

Conflicts:
	src/com/eleybourn/bookcatalogue/CatalogueDBAdapter.java
Merge branch 'master' into incrementals
Remove all references to INSTANCE_UPDATE_DATE and simplify update code
Merged with master. Ensures update_date set when child data updated

- Remove all references to INSTANCE_UPDATE_DATE and simplify update code
Merge branch 'incrementals'