Improve display handling and Makefile

[MassimoGirondi]

Hey Ciao!

Some patches to improve the usability:

• X11 display handling
  The primary display can be disconnected (counter-intuitive but it can happen).
  With the previous solution, if the display was not connected, the program crashed.
  This patch improve display handling by searching the primary one. If not found as connected, select the first display in the list.
• Makefile
  Automatically compile and install the software with make install. Install the requirements too.
• .gitignore and prtscn.so file
  Adding a compiled library is generally useless since it would need to be recompiled for each machine.
  Remove it from the tree and avoid to add it again with .gitignore.

[morrolinux]

Neat work!
On a side note, ~/.config folder should really be used only for user configurations, so the makefile target install should copy the python files and the screenshot library somewhere else, I'd suggest /opt/i3expo-ng.
Also could you add a note in the README explaining that the force option to overwrite previous configuration is suggested if after an update i3expo-ng crashes because of some missing config entries?

Thanks for your contribution

[MassimoGirondi]

On a side note, ~/.config folder should really be used only for user configurations, so the makefile target install should copy the python files and the screenshot library somewhere else, I'd suggest /opt/i3expo-ng.

Why not ~/.local/bin? Seems more appropriate for modern systems and does not require root permissions.

Also could you add a note in the README explaining that the force option to overwrite previous configuration is suggested if after an update i3expo-ng crashes because of some missing config entries?

Done!

[morrolinux]

Why not ~/.local/bin? Seems more appropriate for modern systems and does not require root permissions.

Perfect :)