Switch file ops to stdio

- Does away with the O_BINARY abomination
- as a byproduct, plugs an fd leak in wcolorpanel.c:fetchFile()
- sprinkle some fsync()s to files that have been written to (this
  needs to be done everywhere)

+ fix brown paper bag thinko in configure.ac

WPrefs.app/Appearance.c

@@ -402,6 +402,7 @@ static void dumpRImage(char *path, RImage * image)
 
 	fwrite(image->data, 1, image->width * image->height * channels, f);
 
+	fsync(fileno(f));
 	if (fclose(f) < 0) {
 		wsyserror(path);
 	}

WPrefs.app/MouseSettings.c

@@ -699,6 +699,7 @@ static void storeCommandInScript(char *cmd, char *line)
 			fputs(line, fo);
 			fputs("\n", fo);
 		}
+		fsync(fileno(fo));
 		fclose(fo);
 
 		if (rename(tmppath, path) != 0) {
@@ -711,8 +712,10 @@ static void storeCommandInScript(char *cmd, char *line)
 
  end:
 	wfree(path);
-	if (f)
+	if (f) {
+		fsync(fileno(f));	/* this may be rw */
 		fclose(f);
+	}
 }
 
 static void storeData(_Panel * panel)