Reader/Writer should implement Close() to free convertor

reader.go

@@ -5,6 +5,7 @@ import (
 	"syscall"
 )
 
+// This implements io.ReadCloser interface
 type Reader struct {
 	source            io.Reader
 	converter         *Converter
@@ -61,6 +62,11 @@ func (this *Reader) fillBuffer() {
 	}
 }
 
+// Must be called to free memory
+func (this *Reader) Close() error {
+	return this.converter.Close()
+}
+
 // implement the io.Reader interface
 func (this *Reader) Read(p []byte) (n int, err error) {
 	// checks for when we have no data

writer.go

@@ -2,6 +2,7 @@ package iconv
 
 import "io"
 
+// This implements io.WriteCloser interface
 type Writer struct {
 	destination       io.Writer
 	converter         *Converter
@@ -58,6 +59,11 @@ func (this *Writer) emptyBuffer() {
 	}
 }
 
+// Must be called to free memory
+func (this *Writer) Close() error {
+	return this.converter.Close()
+}
+
 // implement the io.Writer interface
 func (this *Writer) Write(p []byte) (n int, err error) {
 	// write data into our internal buffer