irc/xchat. As japanese/xchat "built" without a problem, I didn't
notice it was "broken"... In reality, the configure script failed to
detect the iconv library because of the removal of CPPFLAGS and LIBS
in CONFIGURE_ENV, therefore the built binary lacked Japanese support.
(i.e. the ja-xchat package included in 4.2-RELEASE will be broken)
To avoid this kind of sad accidents in future, add a note to irc/xchat
that it has a slave port and one should be careful not to overwrite
variables or targets.