0.6.1 Firearm serial numbers + fixes

- Added firearm serial numbers to the game:
All firearms will now have a serial number etched onto the side. You can spot this by rotating the firearm in inspect mode, or by reading the examine text when picked up or inspected. A passenger now requires both a permit, and to have the matching serial number on that permit for the firearm to be classed as "allowed", if a passenger has a permit but an incorrect serial number - it needs to be flagged.

Firearm serial numbers are a small part of a future major update to flagging.

- Lowered the height on the low workbench table so bags pushed off the conveyor should now be pushed onto this table.(will tweak as needed)
- Added X-ray zoom control to the bindings page, although it is locked for now and only used as reference.
- Fixed a bug that didn't update your level on the career tab app.
- Fixed a lagg spike when bags reached the end of the conveyor.
- Fixed a bug that allowed passengers to have multiple large blade permits.
- Added a 'What's new' popup on the main menu when important gameplay features are modified.
- Reduced scoring penalization slightly overall, and by around 25-30% on fun mode.(Will adjust more with feedback.)
- Fixed a bug that prevented the poster above the conveyor to move when you purchase conveyor pushers.
- Added a standardized wage of £20 at the end of the day regardless of score payment.(slave labor I know.)
- Misc bug fixes. I appreciate your patience with the delay of this small update, I had to take some time off in the last month due to sickness and a family get together, I am now back in full swing and am working on much larger updates! stay tuned! Craig.