Update outdated and broken holiday stylesheets
Each style was updated by copying qt.css and then adjusting
the required definitions such as background image and color.
foreach(dir
Fonts
Forts
Graphics
Locale
Maps
Missions
Music
Names
Scripts
Sounds
Themes
misc
)
add_subdirectory(${dir})
endforeach(dir)
if(${GL2})
add_subdirectory(Shaders)
endif(${GL2})