condense gp_log_data debug output. - changed gp_log_data to take a printf style debug string -> new major version of libgphoto2_port - adjusted all callers git-svn-id: https://svn.code.sf.net/p/gphoto/code/trunk/libgphoto2@15175 67ed7778-7388-44ab-90cf-0a291f65f57c