versioning.md

1. Check if a resource is versionable and discover the TimeMap/LDPCv
   1. HEAD on the LDPR: Link rel="type" http://fedora.info/definitions/fcrepo#VersionedResource indicates versioning support, Link rel="timemap" points to LDPCv/TimeMap
2. Check if we can create versions
   1. OPTIONS on LDPCv/TimeMap: Allow: POST indicates that versions can be created
3. Create a new version
   1. POST to LDPCv/TimeMap with Memento-Datetime header and body to create a historic version with the specified body and datetime
   2. POST to LDPCv/TimeMap with a body and no Memento-Datetime header to create a version with the specified body and the current datetime
   3. POST to LDPCv/TimeMap with Memento-Datetime header and no body to create a historic version with the current state of the LDPRv and the specified datetime
   4. POST to the LDPCv/TimeMap with no Memento-Datetime header or body to create version with current state of the resource and the resource's last-modified date as the datetime
4. List existing versions:
   1. GET to LDPCv/TimeMap with Accept: application/link-format for link-value serialization
   2. GET to LDPCv/TimeMap without Accept header (or with an RDF type) for an RDF serialization
5. Retrieve an existing version:
   1. GET to LDPRv/TimeGate with Accept-Datetime header
   2. GET to LDPRm/Memento (if the LDPRm/Memento has its own URI)
6. Delete an existing version:
   1. DELETE to LDPRm/Memento
7. Restore an existing version:
   1. PUT to LDPRv/TimeGate with Memento-Datetime header indicating the version to restore (conflicts with LDP)
   2. PATCH to LDPRv/TimeGate with no body and Memento-Datetime header indicating the version to restore
   3. Or: PUT to LDPRv/TimeGate with header (can't be Content-Location, but something like it) pointing to the LDPRm/Memento URI to indicate the version to restore