Fix some problems in the Doxygen-generated man pages (C libraries), the
more noticeable being removing the full path of the files from the
header and synopsis.
owl_send_request() and owl_send_packet() get a boolean "verbose"
parameter that allow to enable or disable message display on run-time
and allow to get rid of the OWLPS_DEBUG compile-time option.
Doxygen comments are now used in libowlps, libowlps-client and
libowlps-resultreader. doc/Doxyfile was added as well as CMake rules to
generate man pages for the libraries' header files.
Instead of #define DEBUG, we now prefer to use either verbose levels
or, when needed, NDEBUG. Each Makefile was modified to be able to pass
-D NDEBUG to the compiler (but the corresponding lines are commented),
except in the modules where assert is never used, in which case the
Makefile passes -D DEBUG.
Long story short: to totally disable debugging code, comment-out the
"-D DEBUG" lines and uncomment the "-D NDEBUG" lines, in every Makefile.
setsockopt(... SO_BINDTODEVICE ...) does not work on OpenBSD. The only
way to force an interface seems to specify its IP address and to use
setsockopt(... IPPROTO_IP, IP_MULTICAST_IF ...). See the code of ping
(-I option).
libowlps-client now builds on OpenBSD!