DiskCount counts SSD spare disks

Our new DiskCount  check counts available disks on a system. This can be quite handy when setting a filter, e.g. only counting SSD drives in the spare container. This way, one can use thresholds to send warning messages as soon as the number of spare SSD disks falls below a certain threshold. In contrast to the previously available check check_netapp_spare, DiskCount can be configured with a detailed set of criteria for its alert messages. Example: ./check_netapp_pro.pl DiskCount ... ‑‑container_type=spare ‑‑disk_type=SSD ‑w 1 ‑c 1 NETAPP_PRO DISKCOUNT OK - 1 disk with matching criteria found. NA17-01 1.1.12: - spare SSD | disk_count=1;1;1;0;