MASTER AGREEMENT BY AND AMONG SEMGROUP, L.P., SEMMANAGEMENT, L.L.C., SEMOPERATING G.P., L.L.C., SEMMATERIALS, L.P., SEMCRUDE, L.P., EAGLWING, L.P., SEMGROUP HOLDINGS, L.P. AND SEMGROUP ENERGY PARTNERS, L.P., SEMGROUP ENERGY PARTNERS G.P., L.L.C.,...