[store][xs]: return CORS headers regardless of status so that js can get error info (fixes #8 https://github.com/okfn/annotator-store/issues#issue/8).
[store][xs]: return CORS headers regardless of status so that js can get error info (fixes #8 https://github.com/okfn/annotator-store/issues#issue/8).

--HG--
branch : feature-accounts

nobita-isc/annotator-store,nobita-isc/annotator-store,happybelly/annotator-store,nobita-isc/annotator-store,ningyifan/annotator-store,nobita-isc/annotator-store,openannotation/annotator-store