FE/Qt: language string updates.
FE/Qt4-OSX: fix the translation of the application menu
FE/Qt4-NLS: updated qt_* translation files to 4.4.3
renamed VirtualBox4 to VirtualBox
purge the obsolete Qt3 GUI
FE/Qt3: Updated the Swedish NLS and the Portuguese Qt NLS.
Updated Finnish, Romanian, Portuguese (Brazil), Catalan, Japanese, Serbian, Italian, Portuguese, Korean, Swedish and French translations for 1.6.
FE/Qt: Updated Portuguese translation and renamed from _pt_PT to _pt (to apply to all Portuguese speaking countries besides Brasil).