Release Gauss v49r20 for Sim09

This is to deploy fixes and new features for Sim09.

A change of version in production SimType is needed Sim09j ➡ Sim09k

It includes:

• !672 (merged) cut for diBoson events
• !676 (merged) new decay model for hyperons
• !693 (merged) bug fix in a decay model for Bs -> mu mu K K
• !694 (merged) new 4-body phase-space decay model in restricted mass window
• !697 (merged) update of reference tests

cc: @adavis, @kreps, @dpopov, @philten