new env loader on machine tag

@marc-hanheide You are completely right, I didn't think about that (the problem of starting things too late at night). 
Now I can think of two options:

I can change `$(env ROS_ENV_LOADER)` for `$(env ROS_ROOT)/../../env.sh` that should work for everyone without defining `ROS_ENV_LOADER` however we would be limited on setting our own environments in case of need or 

I can create a `multimachine` tag (like the remote that was previously installed) and just set the machine tag when there is more than one computer on the system, BUT that would require defining `$(env ROS_ENV_LOADER)` whenever you set this tag.

Can you tell me which one do you think is better? is there anything else I'm missing