A student has cycled 4 000 km (2 500 miles) across West Africa, enduring arrests and blazing heat, for a spot at his dream university. Mamadou Safayou Barry set off from Guinea for Egypt's prestigious Al-Azhar in May, hoping he would be accepted. The 25-year-old cycled for four months through countries wracked by Islamist militants and coups. He told the British Broadcasting Corporation he was "very, very" happy to have …