ndb/tools/waiter.cpp:
  - Only contact ndb_mgmd once per loop
  - Program only cares about ndbd nodes -> remove the api and mgm vectors
  - Program can not wait for "starting" -> remove that code
  - Remove unused includes
  - Protect against SIGPIPE(writing to a socket where the mgmsrv was
    gone, silently killed the program)
  - Don't sleep one second if if all nodes are in the wanted state  
  - Use 100 milliseconds sleep between each poll