Changed version of DSO to show AR

Used Pangolin to perform the visualizations. The main changes were made ar_dso/Pangolin/PangolinDSOViewer.cpp file

Installation

Please refer to the original repository to find the installation instructions: https://github.com/JakobEngel/dso

Along with all the requirements listed in the original repository, you need:

OpenCV 3 only. Open
If you want to have the visualization of DSO work, you need to install Pangolin. Refer to the original repository for the installation instructions. Change the path to the installed Pangolin library in CMakeLists.txt file.

Please refer to the original repository on the instrutctions to run the examples.

The only difference from the original repository is that this one shows the AR cubes in Pangolin visualization window.