WEB CHANGES THAT WILL NEVER HAPPEN
*) Make it possible to introduce a limited set of new @ codes.
5) Add other web tools to the distribution
6) give depend a -F option to list the full pathname???
Look over tangle and add variable controlling when line numbers are
	inserted into |tok_mem|.
put `balance' into spider and document
Write line number inversion tool
Make WEAVE back-end retargetable
Modularize WEB source in two steps: first language split, then
	sensible code.
To parameterize the translation of identifiers.
To parameterize case-sensitivity of language.
Correct TANGLE to include the proper language-dependent meta-comment support. 
Restore @\ ??
Implement @?
