General upgrades can now be purchased from the smith menu.
Added perks.
Fixed a serious typo with buttons.

When destroyed was being called on a button it first called GameObject.init, it should've been calling GameObject.destroy.
Added tabs in the smith menu.
Added weapon content to smith menu. Implementing weapon upgrades.

There's currently a bit of reuse in the menus. This is temporary since we just need a quick testing environment.