Minor updates - inventory, physgun, and notes

**Faustie**

A few minor updates have been made, but they're all so minor that I may as well just group them together in one thread.

The first is the inventory system. Voluptious and I improved size detection, and if you're about to run out of space it'll warn you when your inventory updates with a new item, giving you a bit of leeway when you are, for example, fishing.

The second is the physgun. Admins can now use their physgun on nearly all props, with the exception of world doors and as many lifts as I could restrict. Be careful with the office lift - it's very easy to break, so don't physgun it.

Players will also be able to use their physgun on their own notes, which should make life infinitely easier for builders who use notes.

And, finally, I've increased the character limit on notes slightly, to 150. I'm not sure if you can actually reach this limit as source might get in the way, but it's certainly better than before. I tried to increase the chatbox limit too, but I didn't have success here. I'll try and revisit it later.