Bug #82103 Document DUMP 7021

Description:
Currently DUMP 7021 is not documented. DUMP 7021 is the same as DUMP 7015 but for a single table. When debugging specific tables, it can be useful to reduce the output of 7015 to just that/those table(s) in question.

DUMP 7021 takes a single table id as an argument:

shell$ ndb_show_tables
...
id    type                 state    logging database     schema   name
...
12    UserTable            Online   Yes     world        def      City

shell$ ndb_mgm -e "ALL DUMP 7021 12"
Connected to Management Server at: localhost:1186
Sending dump signal with data:
0x00001b6d 0x0000000c 
Sending dump signal with data:
0x00001b6d 0x0000000c

The Cluster log now contains something like:

2016-07-05 09:59:22 [MgmtSrvr] INFO     -- Node 1: Table 12: TabCopyStatus: 0 TabUpdateStatus: 0 TabLcpStatus: 3
2016-07-05 09:59:22 [MgmtSrvr] INFO     -- Node 1:  Fragment 0: noLcpReplicas==0  0(on 1)=32(Idle) 1(on 2)=32(Idle)
2016-07-05 09:59:22 [MgmtSrvr] INFO     -- Node 1:  Fragment 1: noLcpReplicas==0  0(on 1)=32(Idle) 1(on 2)=32(Idle)
2016-07-05 09:59:23 [MgmtSrvr] INFO     -- Node 2: Table 12: TabCopyStatus: 0 TabUpdateStatus: 0 TabLcpStatus: 3
2016-07-05 09:59:23 [MgmtSrvr] INFO     -- Node 2:  Fragment 0: noLcpReplicas==0  0(on 1)=32(Idle) 1(on 2)=32(Idle)
2016-07-05 09:59:23 [MgmtSrvr] INFO     -- Node 2:  Fragment 1: noLcpReplicas==0  0(on 1)=32(Idle) 1(on 2)=32(Idle)

How to repeat:
See http://dev.mysql.com/doc/ndbapi/en/ndb-internals-dump-commands.html - DUMP 7021 is missing.

Suggested fix:
Add a page for 7021 and probably change the page for 7015 to note it's the same as 7021 for each table and refer to 7021 for details.

Thank you for your bug report. This issue has been addressed in the documentation. The updated documentation will appear on our website shortly.