HBASE-9421 Provide better error message when dropping non-existent namespace



git-svn-id: https://svn.apache.org/repos/asf/hbase/branches/0.96@1520136 13f79535-47bb-0310-9956-ffa450edef68
HBASE-9414 start-hbase.cmd doesn't need the execute flag

git-svn-id: https://svn.apache.org/repos/asf/hbase/branches/0.96@1520163 13f79535-47bb-0310-9956-ffa450edef68
HBASE-9412 Startup scripts create 2 .out files

git-svn-id: https://svn.apache.org/repos/asf/hbase/branches/0.96@1520164 13f79535-47bb-0310-9956-ffa450edef68