Extend Insight API

* Add support for multiple milestones
* Add support for an action button
Improve InsightDAO API

* Add support for header_image in getInsight, insertInsight, and
updateInsight
* Add support for empty text field
InsightDAO API: throw exception if serialized related_data exceeds MySQL text field length
Insights redesign
* Remove dashboard & related assets/tests
* Switch to Bootstrap semantics
* Add redesigned Twitter & Facebook account management for hosted app
* Implement new navigation menu
Don't serialize users setPeople call
More insight cleanup and redesign
Fix broken TestOfReplySpike
Fix broken WebTestOfDeleteInstance
Update many insights to use new API and have shorter headline text. Add stubs for tests needed.
Fix display of related posts in insights and biggest fans insight text.
Merge branch 'insights-redesign-20140112' of https://github.com/anildash/ThinkUp into insights-redesign-20140112

Conflicts:
	webapp/plugins/insightsgenerator/insights/biggestfans.php
	webapp/plugins/insightsgenerator/insights/favlikespike.php
	webapp/plugins/insightsgenerator/view/favlikespike.tpl
	webapp/plugins/insightsgenerator/view/replyspike.tpl
	webapp/plugins/insightsgenerator/view/retweetspike.tpl