Help with compiling on Linux

[ReenigneArcher]

Firstly, thank you for this library! We've had many requests to add a system tray icon and I found your library to be the easiest way to implement this, versus using the windows API.

I have it compiling on Windows and macOS, but I seem to be missing something on Linux.

Trying to build on Ubuntu, Fedora, and Archlinux, but will just focus on Ubuntu/Debian for the purposes of this discussion. So I installed libappindicator3-dev (also tried libappindicator-dev), with no success, so I'm thinking I'm missing something in our CMakeLists.txt. I'd be very grateful if anyone could take a look and offer some guidance.

PR -> https://github.com/LizardByte/Sunshine/pull/1035/files

[ReenigneArcher]

I got it to compile on Archlinux, Fedora and Ubuntu, but still failing on Debian. The libappindicator3-dev package on Debian seems different from the one provided by Ubuntu. Looks like #8 may help take care of that.

Archlinux - libappindicator-gtk3
Fedora - libappindicator-gtk3-devel
Ubuntu - libappindicator3-dev