gpg-crypt: Add the gpg-crypt/gpg-decrypt scripts

These two scripts allow to quickly cipher a message with asymmetric
ciphering. It will ask for options (private-key, public-key, message)
through an editor like vim and display the result in this editor.
qrcode-wifi: Add the qrcode-wifi script

This script allows to create a qrcode which contains the connection
information for a WiFi network. It will request for the necessary
informations and create the qrcode. It will then display it with Feh
for scanning or saving into another file.