realsense_playback needs work

[jackjansen]

Creating a branch for this.

• Non-master bagfiles need to be synced to master
• inpoint and outpoint should be specifiable in cameraconfig
• there needs to be an option on what to do with the missing frames at the beginning of the recording (not all cameras started yet): either don't produce point clouds until all cameras have been started or produce point clouds where some of the captures are in the future.

[jackjansen]

I think we are going to need to use the rs2::syncer class for playback.

[jackjansen]

I think it has improved enough to merge.