all: single space after period.

The tree's pretty inconsistent about single space vs double space
after a period in documentation. Make it consistently a single space,
per earlier decisions. This means contributors won't be confused by
misleading precedence.

This CL doesn't use go/doc to parse. It only addresses // comments.
It was generated with:

$ perl -i -npe 's,^(\s*// .+[a-z]\.)  +([A-Z]),$1 $2,' $(git grep -l -E '^\s*//(.+\.)  +([A-Z])')
$ go test go/doc -update

Change-Id: Iccdb99c37c797ef1f804a94b22ba5ee4b500c4f7
Reviewed-on: https://go-review.googlesource.com/20022
Reviewed-by: Rob Pike <r@golang.org>
Reviewed-by: Dave Day <djd@golang.org>
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>

src/net/rpc/server.go

@@ -143,8 +143,8 @@ const (
 	DefaultDebugPath = "/debug/rpc"
 )
 
-// Precompute the reflect type for error.  Can't use error directly
-// because Typeof takes an empty interface value.  This is annoying.
+// Precompute the reflect type for error. Can't use error directly
+// because Typeof takes an empty interface value. This is annoying.
 var typeOfError = reflect.TypeOf((*error)(nil)).Elem()
 
 type methodType struct {
@@ -162,7 +162,7 @@ type service struct {
 	method map[string]*methodType // registered methods
 }
 
-// Request is a header written before every RPC call.  It is used internally
+// Request is a header written before every RPC call. It is used internally
 // but documented here as an aid to debugging, such as when analyzing
 // network traffic.
 type Request struct {
@@ -171,7 +171,7 @@ type Request struct {
 	next          *Request // for free list in Server
 }
 
-// Response is a header written before every RPC return.  It is used internally
+// Response is a header written before every RPC return. It is used internally
 // but documented here as an aid to debugging, such as when analyzing
 // network traffic.
 type Response struct {
@@ -442,7 +442,7 @@ func (c *gobServerCodec) Close() error {
 // ServeConn blocks, serving the connection until the client hangs up.
 // The caller typically invokes ServeConn in a go statement.
 // ServeConn uses the gob wire format (see package gob) on the
-// connection.  To use an alternate codec, use ServeCodec.
+// connection. To use an alternate codec, use ServeCodec.
 func (server *Server) ServeConn(conn io.ReadWriteCloser) {
 	buf := bufio.NewWriter(conn)
 	srv := &gobServerCodec{
@@ -583,7 +583,7 @@ func (server *Server) readRequestHeader(codec ServerCodec) (service *service, mt
 		return
 	}
 
-	// We read the header successfully.  If we see an error now,
+	// We read the header successfully. If we see an error now,
 	// we can still recover and move on to the next request.
 	keepReading = true
 
@@ -638,7 +638,7 @@ func RegisterName(name string, rcvr interface{}) error {
 // RPC responses for the server side of an RPC session.
 // The server calls ReadRequestHeader and ReadRequestBody in pairs
 // to read requests from the connection, and it calls WriteResponse to
-// write a response back.  The server calls Close when finished with the
+// write a response back. The server calls Close when finished with the
 // connection. ReadRequestBody may be called with a nil
 // argument to force the body of the request to be read and discarded.
 type ServerCodec interface {
@@ -654,7 +654,7 @@ type ServerCodec interface {
 // ServeConn blocks, serving the connection until the client hangs up.
 // The caller typically invokes ServeConn in a go statement.
 // ServeConn uses the gob wire format (see package gob) on the
-// connection.  To use an alternate codec, use ServeCodec.
+// connection. To use an alternate codec, use ServeCodec.
 func ServeConn(conn io.ReadWriteCloser) {
 	DefaultServer.ServeConn(conn)
 }