shared-ip ping test added; get_shared_ip changed to get_shared_ips, has same behavior as similar methods for hosts/backups/data-checks
data-checks for each shared-ip section added, double-quoting removed from around psql-issued query
command output comparison added (used for data-checks, to ensure result from psql-issued query matches an expected value, command treated as failure otherwise, even if psql exited with 0)
slight adjustments to min verbosity for command debugging output, to make it easier to get just the got/expected error output from command processing, without all the other informational output