Add Arakoon divergence check through the healthcheck

[wimpers]

Since @JeffreyDevloo (TNX!) create a script to check for Arakoon divergence (see https://github.com/openvstorage/operations/pull/108), it would make sense to turn this into an HC option so you can check a single arakoon or all arakoons and get reporting in CheckMK. Note that this option should be called explicitly as calling it by default will put too much stress on the arakoons.

[JeffreyDevloo]

It'd be kind of hard to specify arakoons. I'd suggest specifying volumes or a backend name since the script starts from the vdisk and goes all the way down the hierarchy to find the underlying namespaces and potential mismatches

[wimpers]

So the script can only be used for ABM, NSM and voldrv Arakoons? What about the framework and config Arakoon?

[JeffreyDevloo]

We'd need to brew something new for those