Fix control window overwrite issue:

[spsvihla]

• allow sat-pref-rig and sat-pref-rot to access nbook (mod-mgr.c) as an extern variable
• added functions conf_open_in_rigctrlwin and conf_open_in_rotctrlwin
• added dailog boxes displaying when the error occurs
• prevent user from editing rig/rot configurations when a control window is open

This is in response to an issue where, if the user opens an editor while the respective control window is also open, then the call to the radio/rotor_conf_save function when the control window is closed overwrites changes made in the editor.