More tweaks and fixes.

Real life got kind of hectic the last few days. I managed to get a few more playtest sessions in, and added some tweaks and fixes.

* Fixed an issue where loading a game that was saved with the gun drawn would make you draw the gun again.
* Fixed ammo amounts displayed on the GUI sometimes being incorrect after loading the game.
* Fixed an issue where you could cause the reload animation on the Leviathan pistol to play multiple times if you hammered the 'R' key.
* Tweaked the Leviathan hip fire accuracy to make it suck a little less.
* Tweaked drawing your weapon so that it can be done with either the LEFT CLICK or the 'R' key.
* Added an interaction hint for drawing your weapon when you have one equipped.
* Added an interaction hint for toggling your flashlight when you have one equipped.
* Added an interaction hint for opening your inventory.