FE/Qt: language string updates.
FE/Qt4-NLS: merged nl and ko.
FE/Qt4-OSX: fix the translation of the application menu
FE/Qt4-NLS: merged ca, ca_VA, ja, zh_TW, nl, pl, it, bg, cs, ko and pt_BR
FE/Qt4-NLS: updated qt_* translation files to 4.4.3
FE/Qt4: updated Korean, Italian, Czech, Polish & Japanese translations
renamed VirtualBox4 to VirtualBox
purge the obsolete Qt3 GUI
Updated Finnish, Romanian, Portuguese (Brazil), Catalan, Japanese, Serbian, Italian, Portuguese, Korean, Swedish and French translations for 1.6.
FE/Qt: Updated Czech, French, Japanese, Korean, Portuguese (Brazil), Romanian and Swedish translations.
Updated the Korean, Czech, Italian, Polish, Brazilian Portuguese and Swedish translations for the 1.5 release.
FE/Qt: Added Korean translation.