Call this function before using any other GTK functions in your GUI applications.
It will initialize everything needed to operate the toolkit.
If you are using `GtkApplication`, you don't have to call init or
init_check; the `GApplication::startup` handler does it for you.
This function will terminate your program if it was unable to initialize the windowing system for some reason. If you want your program to fall back to a textual interface you want to call init_check instead.
GTK calls `signal (SIGPIPE, SIG_IGN)` during initialization, to ignore SIGPIPE signals, since these are almost never wanted in graphical applications. If you do need to handle SIGPIPE for some reason, reset the handler after init, but notice that other libraries (e.g. libdbus or gvfs) might do similar things.