Support for crypting and decrypting

[dbraga]

I should probably use
http://packages.python.org/pyOpenSSL/
for python

and
http://www.ruby-doc.org/stdlib-1.9.3/libdoc/openssl/rdoc/OpenSSL.html
for ruby

Ruby support is low priority for now.
Let the user decide if crypting or not in the configuration file.
Should be step one prior to remote-fix and remote-install