The principal innovation in this release is the ability to run an external command and incorporate its output into the file being edited:

- 2 new active pseudomacros <code>^N^&lt;4014&gt;</code> and <code>^N^&lt;4015&gt;</code> to receive command and return stdout / stderr
- New pseudomacro <code>^NW</code> to return, in the new ALU Q-register, the length of a macro (or -1 if macro not defined)
- New ALU Q-register for return results (e.g. external command result code, <code>^NW</code> result)
- Above fully documented in updated *man* pages and *h-help* topics

Other Highlights:

- Use visible bell to signal errors
- New regression test suite (source only)
- Fixes several unreported issues (git log for details)

New ALU opcodes since version 54:

-  PSHQ    Push contents of Q to R
-  SQEQ    Skip if Q is zero
-  SQNE    Skip if Q is not zero
-  SQGE    Skip if Q is greater than or equal to zero
-  SQLE    Skip if Q is less than or equal to zero
-  SQGT    Skip if Q is greater than zero
-  SQLT    Skip if Q is less than zero

Lots of internal stuff - see git log for details
