Adding decfiles for B(s/d)->aa->4mu where the intermediate scalars are...

Adding decfiles for B(s/d)->aa->4mu where the intermediate scalars are inspired by the muon g-2 and flavour anomalies with mass 1GeV and lifetimee 1fs.

The new decfiles have been tested and produce sensible output. The dekparser script complained about the event type having the same extra flag as some other decays, but this is unavoidable as there are very few free event types with the correct form available (starting with 131140 and 111140).