HBASE-8572 Enhance delete_snapshot.rb to call snapshot deletion API with regex (Ashish Singhi)
HBASE-12464 meta table region assignment stuck in the FAILED_OPEN state due to region server not fully ready to serve (Stephen Jiang)
HBASE-12544 restore ops_mgt section of ref guide.

* checked out file version as of d7f51e^
* redid cherry-pick of changes to ops_mgt.xml from master commit 804444
* fixup with cherry pick of 71ed3b to replace mdash entity with unicode.

Original Author: stack <stack@apache.org>

Signed-off-by: stack <stack@apache.org>
HBASE-11099 Two situations where we could open a region with smaller sequence number (Stephen Jiang)
HBASE-12516 Clean up QA Bot warnings

Signed-off-by: stack <stack@apache.org>