CanTestQuota - checks if xfs prjquota can be tested returns a reason if not.

PrepareQuotaTestImage - prepares an xfs prjquota test image returns the path the the image on success.

WrapMountTest - wraps a test function such that it has easy access to a mountPoint and testDir with guaranteed prjquota or guaranteed no prjquota support.

WrapQuotaTest - wraps a test function such that is has easy and guaranteed access to a quota Control instance with a quota test dir under its control.

ErrQuotaNotSupported indicates if were found the FS didn't have projects quotas available.

Control - Context to be used by storage driver (e.g.

Quota limit params - currently we only control blocks hard limit.