Version 6.0.0:
  -- 2 coredumps
  -- infinite loop in excise-chunks.
  -- provided tilde expansion in file names.
  -- Fixed cntrl C on ibm rs/6000 causing unwanted exits.
  -- WME supported by a justification that got removed was hanging around.
     No longer.
  -- Fix for a type of chunk being built that couldn't be reordered.
  -- Fix to atof to allow it to compile on a NeXT.
  -- Added warnings for things that look like they might be mistyped variables
     or mistyped disjunctions while parsing.
Version 6.0.1:
  -- added a 'version' command to give full version information from the
     interface level.
  -- rearranged the makefile slightly to prevent it recompiling executables
     whenever no object files had changed.
  -- removed the beta test notice from the startup routine.  Why this routine
     duplicates the text in 'soarnews' I'll never understand.
Version 6.0.2:
  -- Made some simple changes to make the code compile on HP Apollos.  I don't
     know if these will work on all HP machines. Time will tell.
  -- Made a few small fixes to lexer.c and to convert.c so that the program
     would compile under straight ultrix cc as well as gcc.
  -- Added a bugfix provided by bob that fixed a problem with a rete
     optimization.  This fixes two outstanding core dumps.
Version 6.0.3:
  -- Made some changes to "recmem.c" to overcome problems with chunk-free
     problem spaces.  This was in reference to bug report #400.
Version 6.0.4:
  -- Missed a use of alloca last time around.  Removed it.
  -- In interface.c a stray use of "printf" was replaced with "print"
     so that output would go to soar managed streams rather than
     standard output.
  -- HP fixes for ISI:
    -- Commented out "struct timeval;" and added include of sys/time.h
       in soar.h
    -- Added "const" decl to predicate function "compare_firing_counts"
       formal parameters in file interface.c to match ANSI spec.
    -- Added "rm = NIL" in function "remove_wme_from_alpha_mem" in
       rete.c to placate the native HP compiler which thinks rm needs
       to be initialized.
    -- Added a cast to (int *) in the call to select in file io.c
    -- In tilde.c added a switch before the include of pwd.h to
       correct a struct decl problem.
  -- Changed makefile so that objects and binaries for multiple machines
     can be maintained in the soar directory to avoid duplicating sources.
     The is achieved by selecting the appropriate make.header.* file
     in the makefile.  Also changed makefile for multi-agent processing.
  -- Added multi-agent capability.  A number of changes were made:
    -- Moved globals to a header file (global_vars.h contains the extern 
       decls and global_vars.c the memory-allocating decls).  This also
       forced the move of associated typedefs and constants -- so the
       tail end of soar.h looks rather messy.  Soar.h really needs to
       be broken into smaller pieces!  If DFLAGS is empty (the default 
       setting in the makefile).  Then the global vars are decl'ed as in 
       earlier versions (before 6.0.4).  If MULTI_AGENT_ENABLED is set
       then the globals are placed into a record (see the end of soar.h)
       and the record is allocated once per agent.  Note that multi-agent
       processing is not fully activated unless a .init.soar.multi file
       is present when soar is run.
    -- To select the proper agent as well as accomodating backward
       compatibility, the macro "current_agent" is introduced to define
       the access path to the proper agent's global data.  This change
       alone affected ~1900 lines of source.
    -- Added commands "create-agents", "select-agent", "agent-go",
       and "schedule" for multi-agent processing.
    -- Added a new file "scheduler.c" which handles the scheduling of
       agents in multi-agent mode.
    -- Added a file "x_interface.c" which defines the X interface to
       multi-agent soar.  The implementation uses only Xlib calls so
       no dependence on a widget set (e.g., Motif) is present.
    -- Added a new file "queue.c" and its header "queue.h".  This is 
       a generic queue abstract data type.  It is used in the
       X display processing of text-io.  Since text-io is occuring in
       separate windows (instead of standard input as in single-agent
       mode) we must queue up the text-io strings until they can be
       processed by an agent.
    -- Stripped all code out of main.c and moved it to init_soar.c
       EXCEPT for the top-level function "main".  This was done to
       facilitate integration with systems which want to control
       Soar (rather than having soar control external systems).  By
       linking with the other object files and redefining main.c
       this is easily accomplished with the stripped down version of
       main.c.
    -- Added a directory under tests: multi/multi.  This directory
       uses the same format as the other test directories but is pushed
       down one level so that it is not processed when "run-all-tests"
       is invoked.  This is because it only works if MULTI_AGENT_ENABLED
       is defined and USE_X_DISPLAY is NOT.  This causes all multi-agent
       I/O to occur in standard I/O.  To run the test, compile soar
       with the above switch setting for DFLAGS in the make.body file.
       Then cd to tests/multi/multi and execute "run-multi-test".  
       This directory also serves as an example of how to setup multi-
       agent processing.
Version 6.0.5:
  -- Added an "obj" directory to hold object files.
  -- Added machine-dependent directories sun4, IRIX, hp700 to the 
     bin and obj directories.
Version 6.0.6:
  -- Fixed bug in makefile that missed where convert.o should be 
     located.
  -- Corrected another bug in makefile that handles machine-dependent
     processing of convert.
