Add Korean flag

I downloaded the famfamfam icon flags and added the Korean one from there, but I had to change the filename from kr.png to ko.png to match the korean language translation

http://www.famfamfam.com/lab/icons/flags/

@ cookiesunshinex: That's because "kr" is the country code for South Korea, but we're working with language codes here. The language code "kr" corresponds to the Kanuri language.

@ Cito: Great! I'll have it added before the next release. Thank you. :)

As a side note, The famfam set has actually - politically correct - flags for both South and North Korea. But since the Internet is irrelevant in North Korea anyway, I think it's reasonable to use the South Korean flag. We need to be pragmatic. If you take it seriously, then using flags for languages is actually a heresy anyway (http://www.cs.tut.fi/~jkorpela/flags.html).

If you want to just use the names for the languages as links, you do not need this module at all. The links are provided by core's Locale (and Content Translation) module(s), which are pure text. If someone would like to add an icon set stylising the language codes, that'd be great - or they could just not use this module and change the text of the language links to e.g. "[lc]".

I also did not challenge the use of the South Korean flag for being used for Korean. I simply noted that the language code and the country code "kr" are two entirely different things (ie. Kanuri and South Korea, respectively). To take another example the other way around: I live in Denmark, where we speak Danish. When I have to tell where I come from, the code is "DK", when I have to name what I speak, the code is "da".