start support for the Japanese language in the Qt version

just the framework and some simple translations

Change-Id: I7653a9c6ab26b391bfe2942d088d233996030576
Reviewed-on: https://code.wireshark.org/review/3134
Reviewed-by: Martin Kaiser <wireshark@kaiser.cx>
Tested-by: Martin Kaiser <wireshark@kaiser.cx>