Add tests for file IO API

tests/wapptest.cc

@@ -5,6 +5,7 @@
 #include "test_str8_array.h"
 #include "test_i32_array.h"
 #include "test_cpath.h"
+#include "test_file.h"
 #include "test_shell_commander.h"
 #include "wapp.h"
 #include <stdlib.h>
@@ -70,6 +71,17 @@ int main(void) {
 		test_cpath_join_path,
 		test_cpath_dirname,
 		test_cpath_dirup,
+		test_wapp_file_open,
+		test_wapp_file_get_current_position,
+		test_wapp_file_seek,
+		test_wapp_file_get_length,
+		test_wapp_file_read,
+		test_wapp_file_write,
+		test_wapp_file_read_array,
+		test_wapp_file_write_array,
+		test_wapp_file_flush,
+		test_wapp_file_close,
+		test_wapp_file_remove,
 		test_commander_cmd_success,
 		test_commander_cmd_failure,
 		test_commander_cmd_out_buf_success,