Merge remote-tracking branch 'jdbranham/master'
ISIS-983: testing neo4j support for todoapp and simpleapp.

changes:
- the todoapp has been changed to use a Set (rather than SortedSet) for ToDoItem#dependencies... would seem that DataNucleus' neo4j support returns an object of the incorrect type.
- the neo4j settings in persistor.properties has been moved to the end (and is commented out).
- replaced tabs for spaces in pom.xml.

With these change the webapps run ok:
* edit in neo4j setting in WEB-INF/persistor.properties
* build using "mvn clean install -P neo4j"
* run using "mvn antrun:run -Pself-host,neo4j -o"

However, note that the integration tests were tested and do NOT pass:
- the issue for simpleapp was that looks like unique index constraints are not implemented,
- the issue for todoapp looked down to ordering of the dependencies collection.

This commit also:
- renames ToDoSystemInitializer to ToDoAppSystemInitializer (for consistency with simpleapp)
- adds a new putDataNucleusProperty in IsisConfigurationForJdoIntegTests
ISIS-983: changing "testDB" to "neo4j_DB" throughout.
ISIS-928: recreating simpleapp archetype
ISIS-928: recreating todoapp archetype
Minor non-functional improvement

Fix warnings in IDE
Fix Javadoc errors
Merge pull request #1 from apache/master

merging back from main