Documentation comments not generated for many synthesized attribute methods

[Jesper Öqvist]

Documentation comments seem to not be generated for many synthesized attribute methods. Attribute declarations receive documentation comments, e.g.,

syn boolean A.isB();

but equations do not receive documentation comments:

eq B.isB() = true;

[Jesper Öqvist]

Generate documentation comments for equations

Add documentation comments, including the @declaredat tag, which were missing for many synthesized equations.

fixes #233 (bitbucket)

→ <<cset 657410e307d0>>