Indeed, it should install an icon to the system directories anyway as application icon in the menus. Another reason to switch to an autoconf-based build system with a "make install", I guess.
For now we can just use the system default icons as notification.
NO! No autoconf! It is better to use cmake. Like all KDE or rpcminer is using. I had in future plan to take care about it so you can assign me this task. Additionally QtCreator also support it.