Suggestion: It might be helpful to promote each of
the .c files to .cxx.
Rationale:
-- The configure/makefile system handles CFLAGS
differently from CXXFLAGS.
-- It is important for the *info programs to
compiled and run in exactly the same environment
as the main fgfs program. Some users depend on
compiler or linker flags such as rpath that
strongly affect the results of the *info programs.
-- There is no downside; you code compiles just
fine as-is under the c++ compiler.
second part of the original commit, for ehofman/sound
