more comprehensive log output

[tooomm]

Script should print e.g.

• when (and why) files get deleted in the process
  (which ones, reason could be because set has been released...)
• some sets get skipped and don't end up in the spoiler file
  (because no cards in a set, or wrong set type for example...)
• spoilerseason ended since no known spoiled cards are there
  --> remove SpoilerSeasonEnabled file
• ...

Basically, the script should always tell when it does something and describe it in an easy way (reasonable amount) - and why.
That helps with e.g. debugging and makes error spotting and usage in general better.