By Sheila Dang HOUSTON (Reuters) -Exxon Mobil said on Monday it greenlit funding its seventh development project in Guyana called Hammerhead, bringing its oil joint venture another step closer to its goal of producing 1.7 million barrels of oil equivalent per day by 2030 from the country. The prolific Stabroek Block off the coast of Guyana is one of the most significant oil discoveries in years and has propelled the South American country to become the world's fastest growing economy. First oil from the ...