strict-prototypes warning fix

I looked into compiling Pidgin with -Wstrict-prototypes and got some warnings from the meanwhile headers. I'm attaching a file with my fixes to address those individual errors.

I then applied that patch to meanwhile CVS. There were some things that didn't apply cleanly, so I started looking into it and found that there were a lot of bad prototypes. I fixed them with the following command line. The second patch (which I'll attach in a moment) is from the first set of changes plus that:

grep "()" .h | grep -v "#define" | sed "s|^([^:]+). ([^ ]+)();|sed -i 's#\2();#\2(void);#' \1|" | grep -v status-changed | grep -v update_watch | bash