partial fix for this bug. more info on what the other half of the fix involves
is in the bug report.


ndb/src/mgmclient/CommandInterpreter.cpp:
  partial fix for bug13985
  
  hold a mutex around printing out events
  hold the mutex also around printing out put of 'status' commands.
  
  this means we don't get
  1 started
  2 started
  2 starting
  
  output.
  
  we'll instead get the event before/after the entire status output.
  Due to the nature of the event arriving before status being updated,
  we'll pretty much always see started AFTER starting.