Suggestion: remove hard inclusion of ORB-SLAM2

[kmfrick]

Including the whole ORB-SLAM2 in the repository is unnecessary, as most users of this will already have their own version of ORB-SLAM2 installed. Moreover, in case updates are made to the original ORB-SLAM2 repo, the version included here will be outdated. I suggest you either include it as a submodule linked to the original repo, or remove it altogether and send users to the original repo in the README.

[russelldj]

I'd agree. I'm working on modularizing this work on my fork since in our case we rely on different SLAM and semantics methods than what is supported, but the overall concept is still very useful.