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
Fix validation of read-only fields inside dicts.

Issue #474 : As the default values are resolved before validation,
the validation method of readonly fields needs to know about an
 eventual default value of the field in order to skip validation if
the value being validated matches the default.

The default value was being fetched from the schema definition, which
raised a KeyError when the read-only field was not in the first level of
the document, but inside a dict.

This is fixed by getting the default value from the schema attribute
instead.

closes #474
Arnau Orriolis
Merge branch 'arnauorriols-readonly-validation__issue-474' into develop
Link to docs for stable release
Merge branch 'develop' into sqlalchemy

Conflicts:
	AUTHORS
Missing GridFS link