FontKit.java style lookup bug in Turkish locale

This fixes a bug in font style lookup in Turkish locale where dotted and dotless "i"s do not match.  For example, "plain" becomes "PLAIN" in English but "PLAİN" (with dotted upper case i) in Turkish. This causes the map lookup to fail and throws IllegalArgumentException when parsing a valid font string.

The fix simply forces to use English locale for the case conversion.

See the post for more details:  http://echo.nextapp.com/site/node/6840