Protect gateway from format-string crashes in data
As a common security measure, printf-style formatting codes are
not allowed to be directly interpreted from a writable segment.
The gateway code currently has the following function call:
osrfLogActivity( OSRF_LOG_MARK, act->buf );
This is a variadic function which expects the 'act->buf' position
to contain a format string and any trailing arguments to be the
values passed to the formatter. Since act->buf is the value of
what we passed in, some data inadvertantly contains format strings,
and since it is a writable segment, the program crashes. Here is
an example of a crash-causing call: