Fix truncated debug message

There is a bug that does not allow an entire robot model to be printed to debug logging because of a 1024 byte limit on the message:

https://github.com/ros/console_bridge/blob/master/src/console.cpp#L75

Instead you only get a truncated version of the model info. As a workaround I thought we could possibly use std::cout and surround it with NDEBUG as discussed in https://github.com/ros-infrastructure/bloom/issues/327#issuecomment-64295814

My fix here probably isn't right though, I welcome corrections and feedback. Thanks!