Provide a way to run custom actions

[alkisg]

Epoptes should provide a way to run custom actions. Let's take an example of "a teacher wants to copy files to his student's desktops, while using Epoptes in an LTSP environment".

The teacher would need to create a bash script and put it in e.g. ~/.config/epoptes/scripts/copy-dir. Epoptes would invoke that script, while passing the selected clients information, IPs, hostnames, usernames etc. The script would run the server-side commands that it needs, e.g. prompting the teacher "which directory do you want to send?", using whatever tools the teacher programmed in it, e.g. zenity.

Finally, the script would output commands for Epoptes to run on the clients, like "cp -a /home/teacher/the-dir-to-copy ~/Desktop/. Implementing a command-line Epoptes tool isn't necessary in this approach, the commands can be sent from the GUI.