0.1.0:    First public release.
0.2.0:    Never released.
0.3.0:    Created explicit "boolean" type.
          Changed all predicates to use the boolean type.
          Created a "file" type.
          Changed the file I/O functions as well as "run" to
          use file objects.
          Added some convenience commands.
          Fixed bugs.
          Wrote an emacs mode for editing shell scripts.
          Rewrote the Makefile.
0.3.5:    Added the "stderr" and "stderr-handler" commands.
          Fixed bugs.
0.3.6:    Bugfixes.
0.4.0:    More bugfixes.
0.4.5:    Never released.
0.5.0:    "run" now returns an object of type "process."
          Added the "alive?" command.
          Changed the refcounter from the disgusting O(n) list
          implementation to an O(1) one.
          Added the "while" command as an efficiency hack. 
0.6.0:    The backslash quote has been removed.
          Use the tilde quote instead.
          Now includes a very simple replacement for readline.
          (This means that readline is no longer required.)
          Bugfixes and usability features.
          Added the "alias-hash" command and the "car-l" command.
          Expanded the manual.
          Added the "chop!", "chop-nl!", "match", and "reverse" commands.
0.6.5:    Bugfixes.
          Added the "chars", "filter", "clone", and "substring?" commands.
0.7.0:    "run" and "run-simple" now return the exit status of the 
          pipeline if the job was launched in the foreground.
          "chop!" and "chop-nl!" now return their arguments.
          Added "begin-last", which is like the "begin" in Scheme.
          Added the "<" and ">" commands.

0.7.5:    Bugfixes.
          The "split" command can now split on any arbitrary set of field 
          separators.
          Added the "void" command and type.
          Added the "repeat" command.

0.8:      Several small tweaks.

