Xcdrdao cannot build with GTK-- 1.2.0 bacause of the incompatibility
of GTK--. If GTK-- is installed, cdrdao port always tries to build
xcdrdao, and fails.
o Support 5-current.
o Do not use posix-threads by default due to thread scheduling problem.
o Change the address of maintainer.
PR: ports/19504
Submitted by: Yasuhito FUTATSUKI <futatuki@debug.gr.jp> (maintainer)