filter: renamed FilterChainElement to Filter
Fixed source domain key bug where updating objects failed
filter: added rough concept of filter references
filter: FilterFactory now also creates adapters
filter: created package filter.reference
filter: added FilterReferenceManager handling linkage logic
filter: removed "binding" annotation from FilterAnnotation

It was never supposed to be there ...
db: added manual creation of "all" view

Necessary to include the custom domain key in the view javascript file.
dadta: removed DbViews from DataSource

That is somewhat redundant, as they are already present in the DB. The
whole DbView object might be redudant ...
db: moved NotificationClientRepository to db package
db: replaced NotificationsDb annotation with named annotation
db: renamed SourceDataRepository to DataRepository
db: added DataSourceRepository for storing DataSource instances
filter: added dataSourceId to FilterChainReference
db: added FilterChainReferenceRepository
main: added static persisting of sources and filter chains
data: added JSON serializing to JsonPointer

Why doesn't jackson support this natively??
filter: FilterChainFactory searches db for matching DataSource