AES: Fix broken CFB and disableContinuousBuffer()

Related to: https://github.com/phpseclib/phpseclib/pull/45
Merge remote-tracking branch 'petrich/patch-3' into petrich

Conflicts:
	phpseclib/Crypt/AES.php
Merge remote-tracking branch 'origin/petrich'

Conflicts:
	phpseclib/Crypt/AES.php