ISIS-427: ApplicationSettings, UserSettings

changing the table name in @PersistenceCapable

also:
- standardising names of the JDO query names in @Query etc
ISIS-566: JdoVersionFacet and enforce @Version

... can only have @Version on one class in hierarchy.

also:
- some minor improvements to tests of the discriminator facet factory
ISIS-567: global flag to disable concurrency checking (ie in an emergency)

in addition:
- added some additional logging into JDO objectstore to see where repository queries (vs ORM walking the graph stuff)
  are being made.