USAGE: dataedit file

'dataedit' allows you to edit .o files created by save_object(), without
having to directly edit the compressed form, and possibly make mistakes
causing the file to restore improperly.

When you start up dataedit, the file is read, and the filename and variables
in the file appear at the top of the menu.  No changes are actually made on
disk until you exit with the 'q' command, or save the new version to a
different file with the 's' command.  Using the 'Q' command leaves the file
in its original form.

Here is a summary of the options available:

d) Delete Variable:

Remove the specified variable and value.

p) Print Expression:

Print the value of a given expression.  The variables may be refered to
using '$varname'.  $$, or $ followed by an non-alphanumeric character
can be used to mean a literal $.

q) Quit and Save:

Save the internal values to the file being edited, and quit.

r) Rename Variable:

Create a new variable with the same value as an old variable, and delete
the old one.

m) Merge Datafile:

Merge values from another data file into the current datafile.  Arrays and
Mappings are merged by simply adding them; other values will produce mismatches
if the variable exists in both objects.  The original version is then kept.

Q) Quit w/o Saving:

Quit, leaving the file on disk unmodified.

=) Set Variable:

Set a variable (or define one, if it doesn't exist already) to a given value.
The value is any expression, as explained under Print Expression.

s) Save as ...

Save the modified file under a new filename.  That filename becomes the 
current filename.