Fix organization's accounts toggle state

The list of accounts would not appear when the organization
was clicked, even though the triangle icon would toggle downward.
Add "Browse this project in Overview" link
Make "analyze in Overview" allow any search or documents
Prompt with a confirm dialog before export to Overview
Disable Overview link when it would export all of DocumentCloud
Add /api/projects/:id.:format. Fixes #57.
Add ?include_document_ids parameter to /api/projects(?:/:id) route. Fixes #25
Merge branch 'link-to-overview' of https://github.com/adamhooper/documentcloud into overview
Merge branch 'overview'
Merge remote-tracking branch 'nathan/fix_org_accounts_listing'