some changes

[cubefury]

Proposed changes:

1. The initial list item height was correct, just had to extend the rectangles drawn down by 1px. Changing the list item height to 15 caused all the elements to be rendered off-center. I reverted list height to 14 and then extending the draw rect down by 1px instead.
2. I don't believe we need the GL11 calls (please correct me if I'm wrong on this, just from my testing I dont think it's necessary)
3. Removed unused trade_disabled texture (was not part of your changes but I realized there wasn't even a png associated with it lmao)
4. Restored adaptable() methods on textures where applicable: we need these in case the element sizes are changed in the future. It allows us to resize the elements without having to remake the textures. In this sense the textures actually don't need to be bigger than (adaptable2+1, adaptable2+1) pixels in size, but we can leave the textures as they are for now.
5. Removed alpha channel on trade_display_text_color, and removed two fields which are now unused as we took out the rounded rect draw call that used them.
6. Resized highlights to ensure that green tradeable highlights are still visible when mouseover-ing a trade.