deprecate pythia6 tests only to necessary

As per #15, remove all but necessary tests. I removed the 2011 configuration test in favor of 2012 only.

For specific generator decays, I went through the tests and have the following:

• (Deprecated) 11164012: {[[B0]nos -> (D~0 -> K+ pi-)(rho(770)0 -> pi+ pi-)]cc, [[B0]os -> (D0 -> K- pi+) (rho(770)0 -> pi+ pi-)]cc}
• (Deprecated) 11174204: {[[B0]nos -> (chi_c1(1P) -> gamma (J/psi(1S) -> mu+ mu- )) K+ pi-]cc, [[B0]os -> (chi_c1(1P) -> gamma (J/psi(1S) -> mu+ mu-)) K- pi+]cc}
• 13144001: [B_s0 -> (J/psi(1S) -> mu+ mu- {,gamma} {,gamma}) (phi(1020) -> K+ K-)]cc
• (Deprecated) 13164051 [[B_s0]nos -> (D0 -> K- pi+) (K*(892)0 -> K- pi+)]cc, [[B_s0]os -> (D0 -> K+ pi-) (K*(892)0 -> K+ pi-)]cc
• (Deprecated) 15874100: [ Lambda_b0 => (Lambda_c+ -> (Lambda0 -> p+ pi-) pi+) anti-nu_mu mu-]cc
• (Deprecated) 18112001: Upsilon(1S) -> mu+ mu- {,gamma} {,gamma}
• (Deprecated) 18412431: Upsilon(4S) -> (Upsilon(1S) -> mu+ mu- {,gamma} {,gamma}) (eta -> pi+ pi- pi0)
• (Deprecated) 22112001: [D0 -> mu+ mu-]cc
• (Deprecated) 24142004: J/psi(1S) -> mu+ mu- {,gamma} {,gamma}
• (Deprecated) 28102062: eta_c(1S) -> p+ p~-
• (Deprecated) 40911011: pp -> {[W+ -> {mu+ nu_mu, e+ nu_e}]cc, (Z0 -> {mu+ mu-, e+ e-})} (H_10 -> b anti-b)
• (Deprecated) 42112000: pp -> (Z0 -> mu+ mu-)
• (Deprecated) 42112002: pp -> (Z0 -> mu+ mu- {,gamma} {,gamma}) ...
• (Deprecated) 42511100: pp -> [W+gamma -> mu+ nu_mu gamma]cc ...

The ones not left might be of interest by IFT EPOS or for tracking, but I have no strong reason to keep them, so if we want to remove all tests, I think it is OK.