Add (import ...) to etc/tak.scm and t/*.scm.

Note that this commit only fixes 'unbound variable' errors. For now
t/dynamic-wind.scm, t/exception.scm and t/ir-macro.scm seem buggy on my
Linux (amd64) machine.

Signed-off-by: OGINO Masanori <masanori.ogino@gmail.com>

etc/tak.scm

@@ -1,3 +1,7 @@
+(import (scheme base)
+        (scheme time)
+        (scheme write))
+
 (define (time f)
   (let ((start (current-jiffy)))
     (f)

t/closure.scm

@@ -1,3 +1,6 @@
+(import (scheme base)
+        (scheme write))
+
 (begin
 
  (define foo (lambda (a)

t/dynamic-wind.scm

@@ -1,3 +1,6 @@
+(import (scheme base)
+        (scheme write))
+
 (define (print obj)
   (write obj)
   (newline)

t/exception.scm

@@ -1,3 +1,6 @@
+(import (scheme base)
+        (scheme write))
+
 (define (print obj)
   (write obj)
   (newline)

t/ir-macro.scm

@@ -1,3 +1,6 @@
+(import (scheme base)
+        (picrin macro))
+
 (define-syntax aif
   (ir-macro-transformer
    (lambda (form inject cmp)

t/letrec.scm

@@ -1,3 +1,6 @@
+(import (scheme base)
+        (scheme write))
+
 (define (print obj)
   (write obj)
   (newline)

t/tailcall.scm

@@ -1,6 +1,10 @@
+(import (scheme base)
+        (scheme write))
+
 (define (sum k acc)
   (if (zero? k)
       acc
       (sum (- k 1) (+ k acc))))
 
-(display (sum 1000 0))
+(write (sum 1000 0))
+(newline)