Merge pull request #78 from petrich/master

3DES/Rijndael/AES: Fix memory leak with CTR mode
DES: Fix memory leak in OFB mode
Merge branch 'master' of https://github.com/phpseclib/phpseclib
TripleDES, Rijndael: Fix overflow in OFB mode
DES: $block wasn't defined
Merge pull request #5 from phpseclib/master

Sync