move set_nonblock, create_socket and path_exists to libi3

libi3/get_config_path.c

@@ -11,15 +11,6 @@
 #include <string.h>
 #include <sys/stat.h>
 
-/*
- * Checks if the given path exists by calling stat().
- *
- */
-static bool path_exists(const char *path) {
-    struct stat buf;
-    return (stat(path, &buf) == 0);
-}
-
 /*
  * Get the path of the first configuration file found. If override_configpath is
  * specified, that path is returned and saved for further calls. Otherwise,