FATAL ERROR with ?auto_decays =true

[Bijan Chokoufe Nejad]

model = MSSM
unstable su1 () { ?auto_decays = true }

produces

FATAL ERROR: Phase-space: generation failed

since it tries to compute su1 => d, ch1+ though msu1 and mch1 are both 1 TeV.

[Juergen Reuter]

Maybe we can do that a little bit earlier!?

[kilian]

Adjusted policy for auto decays: mass equality no longer allowed (even prepared for tolerance parameter which is currently zero). If no decays are allowed for a particle, this is now caught as a non-fatal error, the particle is then kept as stable. r6436.