* first pass at having C code generate feature flags
* Add UI command and cleanup for netplan info
* Make NETPLAN_VERSION defined in Makefile
* Do a better job at checking version and allowing versions under 2.X
* Add feature-flags for renderers
* Add indent for netplan info output
* Add 'info' DBus method
* Define GCOV such that it can be overriden if necessary
* Ensure URL for netplan website returned from 'netplan info' is HTTPS
* Explicitly skip coverage for systemd-dbus code not captured in cov
* Add CLI tests for 'netplan info'