[tools] uav-viewer.py should be updated

[jmplaza]

1. to accept YML configuration files instead of ICE style, old fashioned, cfg files.
2. to use Comm interface instead of direct ICE interfaces
3. to be written in Python 2.7 instead of Python 3.5
   There is a similar example of adaptation here

In addition we should decide among uav-viewer in C++ or uav-viewer in Python. Which one should we use? The other one would be marked as deprecated and no longer maintained.