[FEATURE] Mildly Useful Rubber Stamps

[Mordent]

NOTE

The below is out of date. Please check this post for the current status.

Effect(s)

• Adds the ability to hit a rubber stamp with an ID to give it its "assignment" (e.g. "Geneticist", "Scientist", "Batman", "Lord of Darkness").
  
• Rubber stamps now include their assignment when added to paper: This paper has been stamped with a Clown's rubber stamp.
  
• If no assignment has been given to the rubber stamp it simply says: This paper has been stamped with a rubber stamp.
  
• Adds un-reassignable stamps in department head's offices (added to both Cogmap2 and Destiny), with unique coloration and fixed as the relevant assignment (Captain, Head of Personnel, Head of Security, Chief Engineer, Medical Director, Research Director).
  

Testing

• I tested on my local build (my changes on top of the goonstation-2016-byond510 branch) and it seems fine.
  

Code

• Link to changes (hold off merging, tweaks to come)
  

Thoughts/Suggestions

• I'm torn on whether to make standard rubber stamps un-reassignable once assigned or not. I can see arguments for both sides. Happy to take suggestions.