4.6.0

• [loader] fix: Detect if init has been called in an onload callback
• [core] fix: Use correct frame for inboundFilter methods
• [core] ref: Multiple init calls have been changed to "latest wins" instead of "ignore all after first"
• [core] feat: Introduce flush method which currently is an alias for close
• [node] feat: If options.dsn is undefined when calling init we try to load it from process.env.SENTRY_DSN
• [node] feat: Expose flush and close on Sentry.*
• [node] feat: Add sentry to express error handler response which contains the event_id of the error