MX V5.1 ECO 06, 09-MAR-1999

Change description:

   * Add some armor plating to the FLQ_CLEANUP routine
     to protect against some "should never happen" cases
     in the in-progress message cleanup code path.

Installation:

    1. Copy the appropriate images (VAX or Alpha) to MX_EXE:

          $ COPY MX_ROUTER.{AXP|VAX}_EXE MX_EXE:*.EXE
          $ COPY MX_FLQ_MGR.{AXP|VAX}_EXE MX_EXE:*.EXE

    2. Shutdown and restart the SMTP server:

    	  $ MCR MX_EXE:MCP SHUTDOWN ROUTER,FLQ_MGR
          $ @SYS$STARTUP:MX_STARTUP ROUTER,FLQ_MGR

* If you have a mixed VMScluster with both VAX and Alpha systems,
  you will need both images - one for each architecture.

* If you run the Router and/or FLQ Manager on multiple nodes in your
  cluster, you should execute step 2 on each of the nodes currently
  running either of those agents.