Fix for HPUX

We have a stub for sendto in logging_test.c. In HPUX this function
returns int instead of ssize_t, therefore we need a separate stub
for HPUX.

Removing DEBUG definition

This was added to try to compensate for the missing symbol when compiling on HPUX.
I added the real symbol instead by including cf3globals.c to the compilation stage.

Include cf3globals.c only when compiling for HPUX
New stub for Solaris

Solaris people in their infinite wisdom decided to play trickery on
the symbols. Therefore we require a new stub for sendto on Solaris.
Merge pull request #583 from cduclos/master

Fixes for HPUX and Solaris