HoI4 small flag generation

[IohannesIohannium]

The flag generation for HoI4 would simply output .tga files sized 82x52, 41x26 and 10x7 pixels.

The small flag could be somewhat improved graphically, so as to be more recognizable to the eye, by the following edits:

• Adding the following lines to 00_magic.lua:

  COUNTRY_FLAG_SMALL_TEX_WIDTH = 16,
  COUNTRY_FLAG_SMALL_TEX_HEIGHT = 11,

• Generate a 16x11 pixel sized small flag instead
• Applying the following mask () to the output small flag

As a comparison:

[Idhrendur]

What does 16x10 look like? It'd be closer to the ratio for the other flag sizes.