Option 1: Integrate DWO back-end with PTAM.

[strasdat]

This is more complicated because of the license issue, but I think there are ways around.

Apart from this, I'd recommend the following steps:

• First, integrate PTAM with pangolin. Check whether PTAM still works well.
• Second, integrate PTAM with the ScaViSLAM::FrameGrabber (and set the PTAM distortion model to identity).
  This requires to write some wrappers between Eigen+OpenCV and TooN+CVD. Check whether PTAM still works well.
• Replace the pointer-based map structures in PTAM with index based map structures. Again, check whether PTAM still works well!
• Finally remove the BundleAdjuster from PTAM and integrate PTAM with DWO.