Remove the limitations built into the decipher binary

Here's a nice task that I recommend everybody tries in order to learn a bit about editing existing scripts

When you examine the source code from "decipher" in the manual, it appears that this tool is originally bundled with an insanely unefficient limiter
The tool parse the entirety of the file to decrypt, then checks if there's multiple lines
If that's the case, it then asks to the user which one to decrypt, instead of decrypting everything
In fact, this selector makes for one HALF of the source file!

By simply moving a few portions of the code, it's rather easy to change it to decrypt all the lines and making the whole selector obsolete
Then, once the script has been simplified, with a bit of knowledge it's possible to hack the file loading part to allow to decrypt a parameter directly to avoid making one file for one single line : the only trick is that an error message tries printing data about the file rather than the lines themselves