let's make this even more easier
if rc is found, it will use last spot, e.g. 0.12.0.0.0.7
release will use the spot before
0.12.0.0.1.0

- that will give us 0.12.X.X  for numbering, which is more than enough (feel free to document to dev release notes)
and the last 2 numbers for figuring out if this is RC or a release ... OK ?
@vladak got better idea (since I am not an IPS expert, but above algorithm is just too complicated for what it wants to achieve) ?