Added check in MerkleSampler for 2*logN worst case check
Added check in MerkleSampler for 2*logN worst case check

Signed-off-by: Andrew Miller <f0442c9cd3d94efe02b427b41caba422bdf18b74@dappervision.com>

amiller/redblackmerkle,amiller/redblackmerkle