make gramar almost conflict free, not considering inner sigmas
no post-processing any more, use Frege comments in grammars
proof that frege comments in grammars work
support frege comments in grammars and byacc 1.9
remove all non-frege comments
functions that deal with Either SigmaS TauS
Merge branch 'master' of https://github.com/Frege/frege