HBASE-8545 Meta stuck in transition when it is assigned to a just restarted dead region sever

git-svn-id: https://svn.apache.org/repos/asf/hbase/trunk@1484875 13f79535-47bb-0310-9956-ffa450edef68
HBASE-8575 TestDistributedLogSplitting#testMarkRegionsRecoveringInZK fails intermittently due to lack of online region (Jeff Zhong)



git-svn-id: https://svn.apache.org/repos/asf/hbase/trunk@1484899 13f79535-47bb-0310-9956-ffa450edef68
DOC: Adding chapter for coprocessors

git-svn-id: https://svn.apache.org/repos/asf/hbase/trunk@1484904 13f79535-47bb-0310-9956-ffa450edef68