* Add basic support for v2 hashes in transmission-show
* Add sha256 for more libraries
* Fix issue with sha256 digest length
* Add sha256 for polarssl
Note: Bumping miniumum PolarSSL version to 1.3 because of
sha2->sha256 name change.
* Add sha256 for CommonCrypto/ccrypto
* Add sha256 for cyassl
