Merge pull request #2 from mirzashah/hydro-devel

Python 3
pytho 3 compatibility
Merge branch 'hydro-devel' of github.com:dirk-thomas/ros_comm into hydro-devel
make order of header fields deterministic
python 3 compatibility
python 3 compatibility
rosbag python 3 compatibility
rosbag python 3 compatibility
rosbag python 3 compatibility
rosbag python 3 compatibility
rosbag python 3 compatibility
rosbag python 3 compatibility
rosbag fix indentation of bmr files
rosbag python 3 compatibility
Merge pull request #3 from dirk-thomas/test

rosbag python 3 compatibility
Python 3
Python 3
Python 3
Python 3
Python 3