59.0: Support for Conflicts and replan on finish

* Added support for Conflicts field
* Option replan is now string expecting "finished" or "immediate"
* Huge amount of changes in dependencies and packages description in SAT
  solver
* Only single approved state is now stored
* pkgupdate has now --no-replan option to ignore replans
* Running Script with same name multiple times is no longer allowed
* Userlists in entry.lua are ensured to be included only once ignoring
  duplicates