-Added CiphertextException to deal with the case where an ICiphertext of the wrong type is passed to an ICryptoType to decrypt.
-Created the ExponentialElGamalCiphertext class
-Small fixes to ICiphertext and DHExponentialElGamal.
-Minor comment changes, etc., to everything else in the changelog
-Created IProof skeleton file.
-Comment to ExponentialElGamalCiphertext
More Crypto changes