Adding a new package for playing back video in conjunction with rosbag

This add the strandsbag package that will have launch files for creating a rosbag together with compressed videos and then playing them back later as though they were image topics. The code right now is only for pulling for the last images and publishing them, this will have to be done based on their timestamps. We will also need a python thread that decomposes the videos as they are needed. This will probably be done in a totally separate node since the play_images already looks for the latest image file to publish. The request also incorporates and important bugfix for the naming of the recreated images.