int opkg_install_package (opkg_t *opkg, const char *package_name, opkg_progress_callback_t callback, void *user_data);
int opkg_remove_package (opkg_t *opkg, const char *package_name, opkg_progress_callback_t callback, void *user_data);
int opkg_install_package (opkg_t *opkg, const char *package_name, opkg_progress_callback_t callback, void *user_data);
int opkg_remove_package (opkg_t *opkg, const char *package_name, opkg_progress_callback_t callback, void *user_data);