go.talks: fix build
Mark those files that should not be compiled by the builder with build tags.
Verified optically that slides are not affected by this.

Fixes golang/go#4983.

R=golang-dev, iant
CC=golang-dev
https://golang.org/cl/7625047
diff --git a/2010/io/balance.go b/2010/io/balance.go
index a3825cb..e808322 100644
--- a/2010/io/balance.go
+++ b/2010/io/balance.go
@@ -2,6 +2,8 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
+// +build ignore
+
 package main
 
 import (
diff --git a/2010/io/decrypt.go b/2010/io/decrypt.go
index e63418b..f00484f 100644
--- a/2010/io/decrypt.go
+++ b/2010/io/decrypt.go
@@ -2,6 +2,8 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
+// +build ignore
+
 // This code differs from the slides in that it handles errors.
 
 package main
diff --git a/2010/io/encrypt.go b/2010/io/encrypt.go
index 57c888c..bfc0526 100644
--- a/2010/io/encrypt.go
+++ b/2010/io/encrypt.go
@@ -2,6 +2,8 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
+// +build ignore
+
 // This code differs from the slides in that it handles errors.
 
 package main
diff --git a/2010/io/eval1.go b/2010/io/eval1.go
index 582f43e..85b0649 100644
--- a/2010/io/eval1.go
+++ b/2010/io/eval1.go
@@ -2,6 +2,8 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
+// +build ignore
+
 package main
 
 import (
diff --git a/2010/io/eval2.go b/2010/io/eval2.go
index 6f826e1..68e278f 100644
--- a/2010/io/eval2.go
+++ b/2010/io/eval2.go
@@ -2,6 +2,8 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
+// +build ignore
+
 package main
 
 import (
diff --git a/2012/10things/8.go b/2012/10things/8.go
index 4d68b52..4b41cc2 100644
--- a/2012/10things/8.go
+++ b/2012/10things/8.go
@@ -1,3 +1,5 @@
+// +build ignore
+
 package main
 
 import "fmt"
diff --git a/2012/10things/9.go b/2012/10things/9.go
index 717ed3b..925bb7d 100644
--- a/2012/10things/9.go
+++ b/2012/10things/9.go
@@ -1,3 +1,5 @@
+// +build ignore
+
 package main
 
 import (
diff --git a/2012/10things/9b.go b/2012/10things/9b.go
index 90bebcd..ae2e74a 100644
--- a/2012/10things/9b.go
+++ b/2012/10things/9b.go
@@ -1,3 +1,5 @@
+// +build ignore
+
 package main
 
 import (
diff --git a/2012/insidepresent/socket-simple.go b/2012/insidepresent/socket-simple.go
index aebadf9..ab388bc 100644
--- a/2012/insidepresent/socket-simple.go
+++ b/2012/insidepresent/socket-simple.go
@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
-// +build !appengine
+// +build !appengine,ignore,OMIT
 
 package main
 
diff --git a/2012/insidepresent/socket.go b/2012/insidepresent/socket.go
index d3f54d6..081be8d 100644
--- a/2012/insidepresent/socket.go
+++ b/2012/insidepresent/socket.go
@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
-// +build !appengine
+// +build !appengine,ignore,OMIT
 
 package main
 
diff --git a/2012/insidepresent/websocket.go b/2012/insidepresent/websocket.go
index 6d1547d..fa0efd3 100644
--- a/2012/insidepresent/websocket.go
+++ b/2012/insidepresent/websocket.go
@@ -1,3 +1,5 @@
+// +build ignore,OMIT
+
 package main
 
 import (
diff --git a/2012/zen/hello.go b/2012/zen/hello.go
index 9695af9..f097a80 100644
--- a/2012/zen/hello.go
+++ b/2012/zen/hello.go
@@ -1,3 +1,4 @@
+// +build ignore OMIT
 package main
 
 import "fmt"
diff --git a/2012/zen/http.go b/2012/zen/http.go
index 4522c96..f3b25f7 100644
--- a/2012/zen/http.go
+++ b/2012/zen/http.go
@@ -1,3 +1,5 @@
+// +build ignore,OMIT
+
 package main
 
 import (
diff --git a/2012/zen/jsonformat.go b/2012/zen/jsonformat.go
index d2e7fce..fdffcde 100644
--- a/2012/zen/jsonformat.go
+++ b/2012/zen/jsonformat.go
@@ -1,3 +1,5 @@
+// +build ignore,OMIT
+
 package main
 
 import ( "encoding/json"; "fmt"; "io"; "os" )
diff --git a/2012/zen/race.go b/2012/zen/race.go
index ad2c549..99ba553 100644
--- a/2012/zen/race.go
+++ b/2012/zen/race.go
@@ -1,3 +1,5 @@
+// +build ignore,OMIT
+
 package main
 
 import ( "fmt"; "net/http"; "time" )