Revised autoreload interface

Make the header only contain the public interface and nothing from the
implementation. All functions get a handle to their self object, like the img_
and tns_ and win_ functions. All necessary data (file path) is also passed as
an argument, so that no extern redeclarations are needed.

Make arl_setup_dir() private, it's not called outside the module.

Make arl_handle() return true if the file has changed, so that the reloading of
the file can be done by the caller.

autoreload_nop.c

@@ -18,14 +18,26 @@
 
 #include "autoreload.h"
 
-void arl_cleanup(void) { }
+void arl_cleanup(arl_t *arl)
+{
+	(void) arl;
+}
 
-void arl_handle(void) { }
+bool arl_handle(arl_t *arl, const char *filepath)
+{ 
+	(void) arl;
+	(void) filepath;
+	return false;
+}
 
-void arl_init(void) { }
-
-void arl_setup(void) { }
-
-void arl_setup_dir(void) { }
+void arl_init(arl_t *arl)
+{
+	(void) arl;
+}
 
+void arl_setup(arl_t *arl, const char *filepath)
+{
+	(void) arl;
+	(void) filepath;
+}