First round of quality of life/bug fixes

Balance
- Adjusted the way weight penalties scale.  Equipping a low to moderate amount of weight should be much more forgiving.
- Increased the effect of proficiency bonuses.
- Increased the effect of preparation.

Items (Applies to newly dropped items)
- Legion Sunder damage changed from 18 to 12
- Legion Sunder weight changed from 12 to 10

Bug fixes and quality of life:
- New Font.  Stats should be more readable.
- Town button now unlocks when your first adventurer dies and properly stays unlocked after reloading.
- Inventory scrap button is now visible only when the smelter is unlocked.
- Active battlegrounds now display their current level.
- Fixed a spacing error in the tooltip of periodic effects.
- Alchemist Time Stone now properly grants madness charges.
- Alchemist Potentus Flask now has the proper duration.
- Alchemist Sinew now has the proper duration.
- Conditionals depending on endurance charge now properly display in tooltips.
- Clearing the final level of a battleground now properly clears the interface for that battleground.
- Town tab now preserves its selection when you switch tabs.