1.2.0
-----
!! This version obsoletes al previous versions! This version fixes
   a bug with the version number write.

v1.1.0
------
!! This version obsoletes version 1.0.x! This new version writes the
   version number to the first 4 bytes of the file. Now we can check
   if we know this version and if we're able to decrypt it.

*  Fixed a bug. Sometimes the last X bytes of a file were not encrypted.
   This is fixed by writing BUF_ALLOC blocks. Now, if the first two longs
   of a block are negative, the block is full size, positive, the  block
   is the length of the first long (all after decryption of course).
