DGEngine v0.1.20

Release for Windows

- add hasEquipedItemType to player
- add subType to item class
- add support to not play sounds that are currently playing
- add support to using previously defined action in new itemClass action
- fix ActPlayerAddToProperty to work with different number types
- refactor player celTexture code
- refactor switch condition to support using previously defined case's actions
- update gamefiles

- add F1-F6 keyboard actions to add/remove gold, life, mana (for testing purposes)
- update player stats code to ignore equipped items that are no longer equipable
- change player texture depending on Armor/Weapon/Shield currently equipped

Note: This is a work in progress. Some things aren't perfect and that's known.
Delete previous saves to avoid error caused by changes.