WowAce

Hendrik Leppkes:
    - Add Bag buttons
    - Show the reagent bank purchase overlay when required
    - Reagent bank fixes
    - Preliminary reagent bank support
    - Hook up the bag/bank open events to actually show the frame
    - Add event handling for bag changes
    - Basics for showing item buttons inside the frames
    - Implement base sizable and movable frame to contain the inventory