Create CryptoStreamWrapper

[KevinMackenzie]

By creating a stream wrapper that provides an SHA-1 hash after the stream is done reading/writing, a lot of time can be saved calculating hashes of downloaded files. This also allows for calculating the SHA-1 hash of an encrypted stream so when checking against a supplied SHA-1 from OneDrive, the metadata can contain both the SHA-1 for the encrypted and the unencrypted data.