oh f6f and p-38 gun fix

Gives the OH F6F-3 and Allen F6F-5 six individual .50 cal machine guns, as did previous release for F4U1, 1A, and F4F-3/-4. Also included is revamped DP for OH P-38, four individual .50 cal guns in nose and a 20 MM cannon. Special "strafer" DP's are included. See README before use...