FE/Qt: language string updates.
FE/Qt: updated NLS prior to translation of 4.3.
FE/Qt4-NLS: merged ca, ca_VA, it, pt_BR
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 Japanese, Italian, Catalan & Hungarian.
FE/Qt4-NLS: Updated Slovak, Galician, Spanish, Catalan, Serbian & Slovak translations. Added Danish.
FE/Qt4-NLS: Updated Catalan, Korean, Italian & Japanese.
FE/Qt4-NLS: Updated Bulgarian, Italian, Serbian, Hungarian & Catalan.
FE/Qt4-NLS: updated qt_* translation files to 4.4.3
FE/Qt4: merged Catalan, Swedish, Italian & Polish translations
renamed VirtualBox4 to VirtualBox
purge the obsolete Qt3 GUI
FE/Qt: Added Catalan translation; Updated French and Spanish translations.