Bug 879475 - Part 001. Add an nsIContentParent api r=jlebar

Based on original patch by David Zbarsky <dzbarsky@gmail.com>
Bug 879475 - Part 002. Add an nsIContentChild api r=jlebar

Based on original patch by David Zbarsky <dzbarsky@gmail.com>
Bug 879475 - Part 003. Use nsIContentParent in indexeddb r=bent

Based on original patch by David Zbarsky <dzbarsky@gmail.com>
Bug 879475 - Part 004. Fix IndexedDBObjectStore to not assume that PContent connects the same processes as PBrowser r=bent

Based on original patch by David Zbarsky <dzbarsky@gmail.com>
Bug 879475 - Part 005. Implement ContentBridge r=jlebar

Based on original patch by David Zbarsky <dzbarsky@gmail.com>
Bug 890570 - Part 006. Fix http auth prompts for nested content processes r=honzab

Based on original patch by David Zbarsky <dzbarsky@gmail.com>
Bug 879475 - Part 007. Allow nested remote mozbrowsers to push layer transactions to the compositor r=mattwoodrow

Based on original patch by David Zbarsky <dzbarsky@gmail.com>