Added basic Experiment type
- Created dexterity type for experiment
- Created (temporary?) top-level folder for experiments
- Created namespace module to centralise referencing of related ontologies
- Created QueryAPI to centralise dataset lookups
- Created index for bccvocab:DataGenre to refine queries
- Created vocabularies for datasets & functions to populate Experiment form
- Created temporary event handler to auto-publish RepositoryItems
- Added collective.z3cform.chosen as package dependency