[FEATURE] Better terminal detection

[ingrinder]

Is your feature request related to a problem? Please describe. At the moment the detected terminal for xterm-compliant terminal emulators is always xterm-256color. It would be nice if this could display the actual terminal emulator in use, e.g. Konsole, gnome-terminal, xterm, terminator, xfce4-terminal, etc...

Ideas for implementing this are:

• Determine the terminal emulator based on parent processes of our process.
  • Could possibly require recursion (e.g. screen sessions)
  • Might not always give a desired result (SSH/mosh?)
• Use known environment variables to determine the terminal emulator
  • e.g. Konsole has $KONSOLE_VERSION, I imagine other terminal emulators also have similar environment variables.
  • Messy! Would require a big list of all possibilities... 😫
• Use X11 to determine current active window (and therefore terminal emulator)
  • e.g. xprop tool.
  • Brings in another dependency...
  • Won't work if the terminal emulator opens in the background.
  • Also won't work on headless systems, or via SSH/mosh.
  • Wayland incompatible (e.g. Fedora)

[HorlogeSkynet]

Not very keen about 1 & 3, but I think we could easily implement 2 (with the current situation as a proper fallback). We could rely on what Neofetch and/or Screenfetch do too, and in the future, one will be 1-PR away from having its-wonderful-terminal-emulator added to the list, and thus supported (as how we currently handle DE & WM) 👌

[HorlogeSkynet]

Closing here as #72 is on its way.