Start fleshing out wayland client implementation

This introduces a basic shared framework for making wayland clients
within sway itself.

swaybg/main.c

@@ -1,6 +1,27 @@
 #include <stdio.h>
+#include <stdlib.h>
+#include <wayland-client.h>
+#include "client.h"
+#include "log.h"
+
+struct client_state *state;
+
+void sway_terminate(void) {
+	client_teardown(state);
+	exit(1);
+}
 
 int main(int argc, char **argv) {
-	printf("Hello world");
+	init_log(L_INFO);
+	state = client_setup();
+
+	do {
+		if (!client_prerender(state)) continue;
+		cairo_set_source_rgb(state->cairo, 255, 0, 0);
+		cairo_rectangle(state->cairo, 0, 0, 100, 100);
+		cairo_fill(state->cairo);
+	} while (client_render(state));
+
+	client_teardown(state);
 	return 0;
 }