Contains the following commits:
HBASE-17748 Include HBase snapshots in space quotas
Introduces a new Chore in the Master which computes the size
of the snapshots included in a cluster. The size of these
snapshots are included in the table's which the snapshot was created
from HDFS usage.
Includes some test stabilization, trying to make the tests more
deterministic by ensuring we observe stable values as we know
that those values are mutable. This should help avoid problems
where size reports are delayed and we see an incomplete value.
HBASE-17752 Shell command to list snapshot sizes WRT quotas
HBASE-17840 Update hbase book to space quotas on snapshots
f262548b1f