AES: don't do mcrypt unit tests if mcrypt extension is not available
Merge pull request #453 from terrafrost/aes-fix

Rijndael, AES: adjustments to what key sizes are and aren't allowed

* terrafrost/aes-fix:
  AES: don't do mcrypt unit tests if mcrypt extension is not available
  AES: a few final changes
  AES: set CRYPT_RIJNDAEL_MODE as well in unit tests
  AES: CS changes to unit tests
  AES: more unit test fixes
  AES: unit test updates
  AES: more unit test fixes
  AES: add new lines to end of unit tests
  AES: CS adjustments to unit tests
  AES: first attempt at unit tests for key padding
  Rijndael, AES: adjustments to what key sizes are and aren't allowed