[cleanup] Fix spelling in a comment
[cleanup] Do not use the 'register' keyword

Compilers are much smarter than programmers, and know best when to use
CPU registers.  Leave the decision to them and do not clutter the code
with the 'register' keyword.
[cleanup] Use correct enum value NOOBJ instead of constant '-1'
[cleanup] Remove non-ascii characters from the file

The (very) old DDD debugger with the (very) old motif gui cannot handle umlauts.
[cleanup] Remove old documentation template
[cleanup] CLEAR and IDENT are enum values now
[cleanup] Remove some debugging code
[cleanup] Remove unused variable
[cleanup] Fix spelling in comment
[cleanup] Remove unnecessary include