[screenshot] Suggest -D, --directory

[Philippe Corbes <philippe corbes gmail com>]

Hello,

I saw in previous messages that I'm not alone to want to take picture without to validate where I want to save picture.
I added a parameter to set where I wish to save pictures. It's  -D, --directory.

First this directory is tested. 
Second, if first directory isn't found then try /tmp directory.
The default value for directory is ./

What do you think about this?
Philippe Corbes