Remote checks enaled

This is for other modules to have the possibility to add nagios checks 

I was quite surprised you were not exporting nagios_commands before!! This is a very interesting feature, and can take all your commands away from the server and put them back to the client part, where they should be. In fact, I will be doing that (in a separate branch, so separate pull request), by making all client checks (and commands) actual exported resources.

I also foresee a cleanup... specially on the custom facts part. Why do you use so many custom facts? Please tell me, I don't like the idea of forking away too much.