Define distinct X timer numbers across all osmo programs
Using osmo_tdef API, we are managing various 3GPP defined T timer numbers (like "T3203")
To add our own timers, we're using X timers (like "X1234").
We should best choose globally distinct X timer numbers for every program and every use.
So far we're seeing a collision of e.g. X1, X2 to mean different things according to context.
That would be fine and is manageable, but it also wouldn't be much of a problem to choose distinct number spaces.
Create a wiki page like Port Numbers for X timers (and maybe also for T timers we have implemented, while at it)
and possibly fix current duplication in recently added X timer numbers