2.5.18 is in beta, and can be tested! Please test this new version and let us know your experiences!
- Removed JetPack SSL fix, as it is now incorporated in JetPack.
- Moved mixed content fixer hook to template_redirect
- Changed flush rewrite rules hook from admin_init to shutdown, on activation of SSL.
- Changed function which checks if admin_url and site_url should return http or https to check for https in home_url.
- Explicitly excluded json and xmlrpc requests from the mixed content fixer, which should resolve compatibility issues with JetPack