Switch to using goroutines rather than a select()

More complex code since now we have to synchronize between threads,
but a good way to teach myself more about goroutines.

tools/utils/io.go

@@ -2,39 +2,6 @@
 
 package utils
 
-import (
-	"io"
-	"time"
-)
-
 const (
 	DEFAULT_IO_BUFFER_SIZE = 8192
 )
-
-type BytesReader struct {
-	Data []byte
-}
-
-type Reader interface {
-	ReadWithTimeout(b []byte, timeout time.Duration) (n int, err error)
-	GetBuf() []byte
-}
-
-func (self *BytesReader) Read(b []byte) (n int, err error) {
-	if len(self.Data) == 0 {
-		return 0, io.EOF
-	}
-	n = copy(b, self.Data)
-	self.Data = self.Data[n:]
-	return
-}
-
-func (self *BytesReader) ReadWithTimeout(b []byte, timeout time.Duration) (n int, err error) {
-	return self.Read(b)
-}
-
-func (self *BytesReader) GetBuf() (ans []byte) {
-	ans = self.Data
-	self.Data = make([]byte, 0)
-	return
-}