- 24 Feb 2014 M.Fuerstenau version 0.9.8
  - Corrected a type in the help()
  - Moved the block for constructing the full path of the sessionfile downward to the authentication
    stuff to have all in one place.
  - Authentication:
    - To reduce amounts of login/logout events in the vShpere logfiles or a lot of open sessions using
      sessionfiles the login part has been rewritten. Using session files is now the default. Only one
      session file per host or vCenter is used as default

      The sessionfile name is automatically set to the vSphere host or the vCenter (IP or name - whatever
      is used in the check).

      Multiple sessions are possible using different session file names. To form different session file
      names the default name is enhenced by the value you set with --sessionfile.

      NOTICE! All checks using the same session are serialized. So a lot of checks using only one session
      can cause timeouts. In this case you should enhence the number of sessions by using --sessionfile
      in the command definition and define the value in the service definition command as an extra argument
      so it can be used in the command definition as $ARGn$.
    - --sessionfile is now optional and only used to enhance the sessionfile name to have multiple sessions.
    - If a session logs in it sets a lock file (sessionfilename_locked).
    - The lock file is been set when the session starts and removed at the end of the plugin run.
    - A newly started check looks for the lock file and waits until it is no longer there. So here we
      have a serialization now. It will not hang forever due to the alarm routine.
    - Fixed bug "Can't call method "unset_logout_on_disconnect"". I mixed object orientated code and classical
      code. (Thanks copy & paste for this bug)
  - $timeout set to 40 seconds instead of 30 to have a little longer waiting before automatic cancelling
     the check to prevent unwanted cancelling due to longer waiting caused by serialization.

Please read the README about session file and usage.
modified:   HISTORY
modified:   README
modified:   check_vmware_esx.pl
modified:   modules/help.pm