- Add remark about optimize
- Remark about "mixed substitution incompleteness"
- Add remark about "%assert" and "safe mode"
- Add remark about "%establish" and "%prove"

- Add Twelf.unsafe

- Add Twelf.Print.sgn
- Add Twelf.Print.prog

- Add TeX remarks
- Add Twelf.Print.TeX.sgn and prog

- Add tracing.

- %name takes optional second argument
- Prefix argument to a few command now selects the server buffer
  (this simplified tracing and breaking)

- Add Twelf.make