Support CP949, fixes #10

This branch supports CP949 separately from EUC-KR:

    $ charade tests/CP949/ricanet.com.xml
    tests/CP949/ricanet.com.xml: CP949 with confidence 0.99
    $ charade tests/EUC-KR/_mozilla_bug9357_text.html
    tests/EUC-KR/_mozilla_bug9357_text.html: EUC-KR with confidence 0.99