Add support for custom fileds API
Add new bus events for custom fields
Fix missing context for RecordIdApi
Add missing external bus events
Add perv/next eventId and event createdDate for SubscriptionTransition
analytics: add missing mappers

Signed-off-by: Pierre-Alexandre Meyer <pierre@ning.com>
Merge remote-tracking branch 'origin/analytics-as-osgi-plugin-support' into analytics-as-osgi-plugin
analytics: integrate with origin/analytics-as-osgi-plugin-support

Signed-off-by: Pierre-Alexandre Meyer <pierre@ning.com>