HBASE-11627 guard against divide by zero in RegionSplitter logging.

Adds a test for noop rolling splits that fails prior to the addition
of the guard.

Signed-off-by: Andrew Purtell <apurtell@apache.org>
HBASE-11708 RegionSplitter incorrectly calculates splitcount

when split table using the util(UniformSplit or HexStringSplit),
with "-r" option, the caculation of splitCount in funciton rollingSplit
may be wrong.

Signed-off-by: Andrew Purtell <apurtell@apache.org>
HBASE-11749 Better error logging when coprocessors loading has failed (Srikanth Srungarapu)