This reverts commit 96953647c3.
* Re-apply "Edit API for replies"
This applies commit 8829a1a412.
* Re-apply "Create a 'transcludedfrom' API endpoint"
This applies commit 5d8f3b9051.
* Re-apply "Use transcluded from API to avoid ever fetching Parsoid DOM in client"
This applies commit 9d0fc184fe.
* Re-apply "Restore error message for when comment is deleted while replying"
This applies commit 655c0526d6.
Change-Id: Id20d21899f87464636022aa0683f8c03e0060117