Send network activity by email
Fixed broken test in invite_controller_test

Clear all jobs in setup method of invite_controller_test to
avoid confusion in tests that look at delayed jobs.
Merge branch 'AI2694-network_activity_email' into stable

Conflicts:
	app/models/person_notifier.rb
	app/views/person_notifier/mailer/_create_article.rhtml
	app/views/person_notifier/mailer/content_summary.rhtml
	test/unit/person_notifier_test.rb
	test/unit/person_test.rb