#24 fix gcc warnings

[Sean Proctor]

I compiled with -Wall and -Werror
This uncovered a number of bugs. And just a bunch of
harmless warnings that I fixed anyway.

in ggenie.c, I can't tell if the warning was showing a
problem or not. I don't know what's really going on
there. You might want to look at i_code and i_comment
and their usage to be sure.

most of the patch is adding missing headers and
functions to headers, etc. part is making parentheses,
etc unambiguous. part is fixing the file chooser stuff
if OK isn't picked.

adding the header/function info caught a couple bugs
with how functions were called.

[Sean Proctor]

cleans up the warnings generated by gcc -Wall -Werror