A group of 22 international human-rights and aid groups issued a report on Tuesday asserting that Israel’s easing of its blockade of Gaza five months ago had made little difference to the people living there. The groups, including Amnesty International and Save the Children, said that construction material was still trickling in and that exports remained banned, meaning that the Palestinian coastal strip could not recover from Israel’s three-week war there two years ago. Israel responded that the report was distorted. It said that nearly twice the amount of goods were going into Gaza compared with earlier this year.