Network stop networkmanager

add 2 options to avoid more conflicts with NetworkManager. by default, nothing will change.

the nmcontrolled option can now also be set network wide (when using this, you will need to set nmcontrolled explicilty to true per device that can be controlled by nm)
allow_nm : when set to false, it will forcefully stop and remove NetworkManager service (it's always better to do this before with ncm-chkconfig)