[FEATURE] Several sleepy pen tweaks.

[Erik]

This patch contains several sleepy pen tweaks.

• You can now alter the amount of reagents injected by the pen by clicking it whilst you are holding it in your hand.
  
• You can now destroy the pen, and turn it back into a real normal black pen!! Woa! Stealthy!!
  

Code: https://github.com/DoomStation/doom/comp...-sleepypen