* Created DRBD->check_if_syncsource() and ->check_if_synctarget() that return '1' if the target host is currently SyncSource or SyncTarget for any resource, respectively.
* Updated DRBD->update_global_common() to return the unified-format diff if any changes were made to global-common.conf.
* Created ScanCore->check_health() that returns the health score for a host. Created ->count_servers() that returns the number of servers on a host, how much RAM is used by those servers and, if available, the estimated migration time of the servers. Updated ->check_temperature() to set/clear/return the time that a host has been in a warning or critical temperature state.
* Finished ScanCore->post_scan_analysis_node()!!! It certainly has bugs, and much testing is needed, but the logic is all in place! Oh what a slog that was... It should be far more intelligent than M2 though, once flushed out and tested.
* Created Server->active_migrations() that returns '1' if any servers are in a migration on an Anvil! system. Updated ->migrate_virsh() to record how long a migration took in the "server::migration_duration" variable, which is averaged by ScanCore->count_servers() to estimate migration times.
* Updated scan-drbd to check/update the global-common.conf file's config at the end of a scan.
* Updated ScanCore itself to not scan when in maintenance mode. Also updated it to call 'anvil-safe-start' when ScanCore starts, so long as it is within ten minutes of the host booting.
Signed-off-by: Digimer <digimer@alteeve.ca>