Schema generation: consider active view, discard non-included properties

[cowtowncoder]

(note: cleaved from FasterXML/jackson-dataformat-csv#93)

It would make sense to filter out properties that are NOT included in the active view (if any), when traversing type hierarchy.

Since this would be non-backwards-compatible change (potentially, but not expected to be so for common cases), it'd make sense to add a SerializationFeature to control behavior. Assumption is, however, that previously users have NOT set a serialization view for traversal, as it has not had any effect formerly.