Rudder

There is no reason to still have cf-clerk and Rudder splitted - it only brings bloat for no gain. Moreover, if the separation should be done today, it would certainly be done differently.

Moreover, the split will grandly complexify the dual promise generation logic in Rudder 3.2 to support one promise by directive output.

This first ticket is only to get source code from cf-clerk and put it into Rudder. It does not:

- change packaging so that cf-clerk is no more built or needed by Rudder
- refactor code to take advantage of the merge - not even renaming packages. Further ticket will allow to really take benefits from the merge.