Adapt paths for OpenNao v2, fix sudo PATH problem, cleanup

Here some suggestions how to improve the bootstrap.sh script. Feel free to cherry pick the changes you like and drop the rest.

* Adapted the paths for OpenNao 2.1.0.19 and 2.1.2.17
* Add the openrobots binary path to /etc/sudoers as secure_path so there's no need to pass the PATH variable via an alias. This should solve the sudo problem #2 
* Added tests for existing files and clean up temporary files after usage

The script works for us on v4 and v5 Naos with OpenNao 2.1.0.19 and 2.1.2.17. We currently don't have 1.14 installed, so we cannot test the script there.