This adds info to the blocks about their size.
Also added two more blocks:
* for experimental features such as in private branches or
  or feature branches. This is for command IDs that are going to
  be merged with master some day. At merge they need to be changed
  and put into the regular position.
* for private features that are not going to be merged into master.
  e.g. specific features for a very specific user that are not
  useful for general audiance.

This should help keeping stuff sorted and largey reducing the risk
of command ID collissions on merges of branches.
Also this should make the merger's job a little bit more easy as
there are less likely any conflicts on merge if someone else got
a number closeby and those change is within the diff's context lines.