fix quotient, make / raise if result not exact

quotient only works for fixnums so far
Ignore the binaries
Add something resembling mutable pairs. Not very tested.
Fix tests

Sadly, we cannot read from a write pipe.
Also, not is not a function in python
fix translation
make quotient work for bigints again
Fix eq? and add test
Fix equal? and add test
Add eqv? and a test
Strings do not eqv via equal but Characters do
Strings do not eqv via equal but Characters do
This is a better name for the primitive
Typo
centralize test helpers
Add funcarg to use the Examples from the Racket documentation directly.

Like that

    def test_string_copy(doctest):
        """
        > (define s1 "Yui")
        > (define pilot (string-copy s1))
        > (list s1 pilot)
        '("Yui" "Yui")
        > (for ([i (in-naturals)] [ch '(#\R #\e #\i)])
            (string-set! pilot i ch))
        > (list s1 pilot)
        '("Yui" "Rei")
        """
        assert doctest
Add 'substring for the strings benchmark (and small test)
Missing file
Add bindings.
Add mzscheme bindings.
Allow #%top to be matched