Fixes object listing with special key names
Fixes object listing with special key names

swift (which prevents storing these keys on its own API) will store
special characters in percent-encoded form, meaning that with the S3
API, when keys were listed, they appeared as percent-encoded, rather
than the original name.

This change uses unquote to resolve the percent-encodings to the
original name when listing keys in the bucket.

These test cases now pass:
tests.functional.test_s3.test_bucket_create_special_key_names

KoreaCloudObjectStorage/swift3,citrix-openstack-build/swift3,stackforge/swift3,KoreaCloudObjectStorage/swift3,citrix-openstack-build/swift3,citrix-openstack/build-swift3,tumf/swift3,citrix-openstack/build-swift3,Zentyal/zentyal-swift-middleware,tumf/swift3,stackforge/swift3,Zentyal/zentyal-swift-middleware,swiftstack/swift3-stackforge,swiftstack/swift3-stackforge