Code cleanup

[mitra42]

Code has had enough changes to be worth a cleanup pass - some items to check are ....

• [x] any TODO's - copy to issues
• [x] move logical stuff together - especially JS routines that can be deleted after replacement
• [x] Check the COLD/WARM/QUIT thinking but see #24
• [x] Move all constants likely to be edited together.
• [x] Make sure using whatever can of new code - e.g. vectoring EXPECT etc
• [x] Clean out forth_v1.js
• [x] Push to Node - moved to #23

README.md

• [x] Installation instructions (depends on Node).- moved to #23

DESIGN.md

• [x] Code - moved to #25