JS mode causes further evaluation of input - is this always needed?

[davidedc]

e.g. in

Algebrite.ANY_FUNCTION(Algebrite.factor('1/2x+3/7'));

ANY_FUNCTION won't get the factored input, cause its argument is evaluated and hence the factors will be re-expanded.

Is this needed? Can this be controlled better? (this came out of the discussion in https://github.com/davidedc/Algebrite/issues/91 )