Convert to/from utf8 in main.cpp. Still not ideal.
Use utf8 functions in game.cpp
Replace some remaining wide_to_narrow calls.
Add notices to conversion functions in string.h
Replace narrow_to_wide with utf8_to_wide in gui*.cpp files.
Convert TOCLIENT_ACCESS_DENIED; make all error messages use utf-8.
Convert some remaining calls to narrow_to_wide.