Fix 200 status code returned on error with PUT and PATCH methods (fix: #384)
Add support for sub-document projection (fix: #182)
Add test for subdocument projection

It doesn't test exclusive sub-document projection as it isn't supported yet.
As discussed in #384, replace validation HTTP status errors by 422 and make it configurable
Merge branch 'subdocument-projection' of github.com:rs/eve into rs-subdocument-projection
flake8
Support for sub-document projections
Merge branch 'rs-subdocument-projection' into develop
Fixes nicolaiarocci/cerberus#48
Improve docs for VALIDATION_ERROR_STATUS
flake8
Merge branch 'rs-fix-edit-error-status' into develop

Conflicts:
	eve/tests/test_settings.py