Separate rosbag_storage from rosbag

Originally filled as #248 by @tfoote

rosbag_storage contains the file manipulation tools but does not depend on the communication libraries. Allowing rosbag to be used at the API level w/o compiling against the communication libraries.

rosbag_storage elements switched to console_bridge from rosconsole

This needs to be paired with: ros/roscpp_core#12