Add some missing css classes for high res flags (#278)

Author: bl00mber

src/style/common/high-res-flags.less

@@ -246,6 +246,12 @@
  .vi { background-position: -336px -336px; }
  .vn { background-position: -360px -336px; }
  .vu { background-position: -384px -336px; }
+ .wf { background-position: -0px -360px; }
+ .ws { background-position: -24px -360px; }
+ .ye { background-position: -48px -360px; }
+ .za { background-position: -96px -360px; }
+ .zm { background-position: -120px -360px; }
+ .zw { background-position: -144px -360px; }
  * {
  box-sizing: border-box;
  -moz-box-sizing: border-box;