Set current namespace to the current module. Fixes #208.

The pconvert-lib printer checks the namespace for (pre-)defined symbols.

If the current namespace is not configured, as what would happen during module
instantiation, user-written functions like my-add1 would be printed differently.
This also affects the error message from the check-expects.

    #lang htdp/isl+
    (define (my-add1 n) (+ n 1))
    my-add1
    (check-expect my-add1 2)

Output:

    Welcome to DrRacket.
    (lambda (a1) ...)

    Ran 1 test.
    0 tests passed.

    check-expect ... error ... :: first argument of equality cannot
    be a function, given (lambda (a1) ...)

    > my-add1
    my-add1

htdp-lib/htdp/bsl/runtime.rkt

@@ -83,13 +83,14 @@
          [else (ph val basic sub)]))))
   (use-named/undefined-handler
    (lambda (x)
-     (and (sl-runtime-settings-use-function-output-syntax? settings)
-          (procedure? x)
+     (and (procedure? x)
           (object-name x))))
   (named/undefined-handler
    (lambda (x)
-     (string->symbol
-      (format "function:~a" (object-name x)))))
+     (if (sl-runtime-settings-output-function-instead-of-lambda? settings)
+         (string->symbol
+          (format "function:~a" (object-name x)))
+         (object-name x))))
 
   ; sharing done by print-convert
   (show-sharing (sl-runtime-settings-show-sharing? settings))