Also adds flag icon for each language.
One limitation is that the language button doesn’t work properly when
accessed via the “more” menu of the page controls.
@BramChen - could you help me choose the most appropriate flags to use
for the variants of Chinese?
Now we’re just using the word “lingo” for the macro defined in
PageTemplate (where the abbreviation is useful), and using the full
word “language” everywhere else.
It’s possible that we should be using “locale” instead of “language”,
what do you think?
Still quite a few details to work out, but this shows the basic idea of
re-using the theme mechanism to handle language plugins.
Comments and questions welcome.
