Make inflight requests use prefixed keys.
Fix GetObjectCreatedAt.
Add comment explaining the contract of IObjectBlobCache.
Remove noTypePrefix.
Fix wrong comment.
Make T explicit.
Revert "Make inflight requests use prefixed keys."

This reverts commit 73290885e1ec0aa86bb2f94ba5ca09e88d186de9.
Align style with other methods.
Make SQLitePersistentCache implement GetObkjectCreatedAt.
Merge pull request #144 from akavache/jsonserializationmixins-fix

Json Serialization Mixins fix