REPL uses dyna compiler to get plans; suppports (to some extent) the addition of

REPL uses dyna compiler to get plans; suppports (to some extent) the addition of
new rules (deletion or rules should be pretty easy to add).

improvements to code load and compile.

Python codegen no longer uses call indirection table.

'and_equals' and 'or_equals' use python 'and' and 'or' instead of python '&' and
'|', which are bit-twiddling operations.