Refactor screen_init(), use methods developed in pimd project

- Refactor screen_init()
  - use native impl. of TTY probing from pimd project
    - check if TIOCWINSZ works
    - check if we're running in watch(1), for initctl
  - check if ANSI goto(999,999) escape seq. works (invasive)
  - fallback to 80x24
- Drop screen_exit()
- Rename screen_init() to get_width(), for now, matching pimd
- Relocate call in main() to banner(), first fn to write to TTY

Signed-off-by: Joachim Wiberg <troglobit@gmail.com>

src/helpers.c

@@ -121,7 +121,7 @@ static void add_console(char *cons)
 	num_cons++;
 }
 
-void console_init(void)
+static void find_active_consoles(void)
 {
 	char *cons, *ptr, *tok;
 	char buf[512];
@@ -148,6 +148,12 @@ void console_init(void)
 	}
 }
 
+void console_init(void)
+{
+	find_active_consoles();
+	screen_init();
+}
+
 ssize_t cprintf(const char *fmt, ...)
 {
 	const size_t len = strlen(fmt) * 2;