OPLOG default settings
OPLOG configuration handling
Refactor for readability and simplicity
OPLOG schema is needed, and it is fixed.

The OPLOG endpoint needs a schema itself because otherwise we would end
up exposing the AUTH_FIELD when User-Restricted-Resource-Access is
enabled.
Change of mind on OPLOG functionality and configuration.

The design so far:

So now the oplog resource is always used to log deleted documents across
API-maintained collections. In time, this will allow to properly handle
If-Modified-Since requests.

However, oplog will also be capable of logging other methods (POST,
PATCH..) Also, the maintainer will be able to make a 'oplog endpoint'
available to clients. This will be a standard API endpoint (can be
configured with auth, url, etc.). Clients might use it to get
a comprehensive list of updates across all API endpoints since their
last visit.
OPLOG implementation
Revert "If-Modified-Since disabled on collection endpoints."

This reverts commit a505abfd96268ac5e7fce00255719cbbb1c7274d.

Conflicts:
	CHANGES
Add links and pagination for versioned requests

When document versioning is on, add `?version=<version_num>` to HATEOAS
`self` links. Also adds pagination links for `?version=all` and
`?version=diffs` requests when results exceed `QUERY_MAX_RESULTS`.

Partially addresses #475.
Add tests for version links
Fix to make version pagination tests pass.
Versioning added to HATEOAS
Merge branch 'jenmontes-issue_eve475' into develop
Merge branch 'develop' into sqlalchemy
Properly escaped curl requests. Closes #487.
More detailed links depending on query or version
Tests for queries in HATEOAS links
Fix failing test
Changelog
Merge branch 'jenmontes-issue_eve464' into develop

Closes #464.
Closes #475.
Merge branch 'develop' into sqlalchemy