create an executable to upload/download settings from servodrives and other monitoring stuff

[jimy-byerley]

In order to manage a segment with many servodrives, it could be nice to have a commandline utility to upload/download settings files to/from servodrives. By settings I mean a desired set of SDOs

• [ ] choose a settings file format (yaml, omron xml files, ...)
• [ ] compare a settings file with current servodrive config ethercat compare 0 settings.yaml
• [ ] upload a settings file ethercat upload 0 settings.yaml
• [ ] download all settings into a file ethercat download 0 settings.yaml
• [ ] download a specified set of settings into a file ethercat download 0 settings.yaml 0640.1 06b0.1
• [ ] get arguments given SDOs ethercat get 0 0640.1 0640.1
• [ ] set arguments given SDOs ethercat set 0 0640.1=1 06b0.1=2
• [ ] monitor SDOs (read periodically) ethercat monitor 2s 0 0640.1
• [ ] list the servodrives in the segment with their manufacturer, version, node id, etc ethercat list
• [ ] measure propagation delays & divergences ethercat time