Write a macro to generate postfix commands
Make the postfix-cmd macro handle 1 argument specially
Add generation of let bindings to defpostfix-command
Define add and sub with defpostfix-command
Correctly splice in the forms of the function body
Add tests for macro output
Add popn function and reimplement arg building in terms of item

The implementation using nth was deeply flawed...
Rebind the stack-name with all args popped off of it
Document the usage of defpostfix-command
Fix tests to properly reflect postfix semantics
Define a macro for generating binary integer ops
Attempt to define a macro for generating binary operator tests
Add debugging prn to macro
Add MVTC macro
Clean up and correct macro

Must eval the op symbol thing twice! Once by referencing it in an
unquoted context, the next by an explicit eval.
Add section delimiting comments
Replace inline pop with pop-cmd
Replace inline swap with swap-cmd
Replace inline sub with sub-cmd
Add other binary ops to the command list