Add dec file on D0 -> K- pi+ pi- pi+ pi0 with different intermediate states

To study a major background source in the D0 -> K- pi+ pi- mu+ nu decay, new dec file on D0 -> K- pi+ pi- pi+ pi0 is created with fractions of different intermediate modes based on PDG:

• 0.034 K*0bar(-> K- pi+) eta(-> pi+ pi- pi0)
• 0.470 K- pi+ omega(-> pi+ pi- pi0)
• 0.152 K*0bar(-> K- pi+) omega(-> pi+ pi- pi0)
• 0.039 K*-(-> K- pi0) rho0(-> pi+ pi-) pi+
• 0.012 K*-(-> K- pi0) pi+ pi+ pi-
• 0.293 K*0bar(-> K- pi+) pi+ pi- pi0